A data storage method for a generalized triangular prism model with vertical side edges

Abstract

The invention discloses a data storage method for cutting a generalized triangular prism model with vertical side edges, and relates to the technical field of three-dimensional geological information models. After establishing a geological model completely composed of generalized triangular prism units with vertical side edges by spatial interpolation of drilling data, the invention constructs a topological relationship between the generalized triangular prism units with vertical side edges and the unit vertices, and at the same time establishes references to the unit vertices and plane points based on the plane position relationship of the unit vertices, and stores the plane points according to a quadtree structure. When calculating spatial cutting, the plane position relationship between the plane points and the cutting surface is first retrieved through the quadtree structure, and then the units to be cut are quickly determined by referencing the unit vertices and units of the plane points, so as to achieve the effects of fast retrieval and storage saving.

Description

Technical Field

[0001] The invention relates to the technical field of three-dimensional geological information models, in particular to a data storage method for a generalized triangular prism model with vertical cut side edges. Background Art

[0002] The generalized tri-prism (GTP) is considered to be a suitable method for expressing three-dimensional geological information models because of its ability to simulate special geological structures such as pinch-out and lens.

[0003] The mainstream method of storing generalized triangular prism data is to express it through a series of three-dimensional points defined in space and their corresponding topological relationships. For example, the invention patent application with publication number CN116522828A, "Method, system, device and medium for reconstructing non-structural linear triangular prism grid units", constructs the surface and volume of the unit through the coordinate information and topological relationship of the vertices of the triangular prism unit. The advantage of this method is that the vertex coordinate information is reused to establish the triangular prism unit containing the same vertex, which saves data storage space to a certain extent. However, this method still has the following disadvantages:

[0004] (1) The triangular prism units are arranged irregularly in space. When the model performs spatial calculations, it is necessary to traverse all the units, which takes up a lot of computing resources.

[0005] (2) This type of generalized triangular prism is difficult to mine the data features of three-dimensional points in the three-dimensional geological information model, and cannot further save data storage resources. Summary of the invention

[0006] In order to overcome the defects in the above-mentioned prior art, the present invention provides a data storage method for sectioning a generalized triangular prism model with vertical side edges. After establishing a model completely composed of generalized triangular prism units with vertical side edges through spatial interpolation of drilling data, a topological relationship between the generalized triangular prism units with vertical side edges and their unit vertices is constructed, and at the same time, references to unit vertices and plane points are established based on the planar position relationship of the unit vertices, and the plane points are stored in a quadtree structure. During spatial sectioning calculation, the planar position relationship between the plane points and the sectioning surface is retrieved through the quadtree structure, and then the units to be sectioned are quickly determined by referencing the unit vertices and units of the plane points, thereby achieving the effect of fast retrieval and saving storage.

[0007] To achieve the above object, the present invention adopts the following technical solutions, including:

[0008] A data storage method for cutting a generalized triangular prism model with vertical side edges, wherein the generalized triangular prism model with vertical side edges, namely, a VGTP model, is composed of a plurality of VGTP groups that are adjacent in space; the VGTP group contains no less than one VGTP unit and its corresponding attribute information; the VGTP unit is surrounded by two upper and lower triangular bottom surfaces and two / three side surfaces; the upper and lower two triangular bottom surfaces are called unit bottom surfaces, and the vertices of the unit bottom surfaces are called unit vertices; the two / three side surfaces are called unit side surfaces, and there are two or more of the unit side surfaces. The edges that intersect and completely overlap are called side edges; the unit bottom surfaces of all VGTP units contained in the VGTP group completely overlap when projected vertically onto the same horizontal plane; the unit side surfaces of all VGTP units contained in the VGTP group that are located on the same vertical spatial plane constitute the group side surfaces; the multiple VGTP groups that are adjacent in space refer to that each VGTP group has at least one VGTP group in the same spatial plane as the VGTP group; the spatial coplanarity refers to that two VGTP groups that are adjacent in space each have one group side surface that completely overlaps or partially overlaps;

[0009] The basic data structure of the data storage method is composed of a root two-dimensional point data chain, n three-dimensional point data chains and a plurality of VGTP group structure relationships;

[0010] The root two-dimensional point data chain includes n non-repeating two-dimensional points, and the n non-repeating two-dimensional points are all the two-dimensional points obtained after all unit vertices in the VGTP model are converted into two-dimensional points by two-dimensional deduplication; the two-dimensional deduplication conversion is to remove the Z coordinate values ​​of all unit vertices and convert them into two-dimensional points, and merge the repeated two-dimensional points into one;

[0011] The n three-dimensional point data chains correspond to n non-repeated two-dimensional points in the root two-dimensional point data chain respectively; the three-dimensional point in the three-dimensional point data chain includes a two-dimensional point X coordinate value reference, a two-dimensional point Y coordinate value reference and a three-dimensional point Z coordinate value; the two-dimensional point X coordinate value and the two-dimensional point Y coordinate value of the corresponding two-dimensional point can be obtained through the two-dimensional point X coordinate value reference and the two-dimensional point Y coordinate value reference in the three-dimensional point data chain; the three-dimensional point is the corresponding unit vertex, and the three-dimensional point Z coordinate value is the Z coordinate value of the unit vertex;

[0012] The composition relationship of the VGTP group includes all information for generating all VGTP units in the VGTP group and their corresponding attribute information.

[0013] Preferably, the root two-dimensional point data chain is stored in a quadtree root-branch-leaf data format according to the plane positions of the two-dimensional points it contains; the quadtree root-branch-leaf data format is:

[0014] A rectangular area on a plane containing all the two-dimensional points in the root two-dimensional point data chain is determined, which is called the root rectangular area; the edge inclusion means that all the two-dimensional points in the root two-dimensional point data chain are located in the root rectangular area or on the edge;

[0015] Repeat the division of the root rectangular area and the rectangular area formed after the root rectangular area is divided in the form of rectangular quartering until the number of two-dimensional points contained in the partial edges of all the leaf rectangular areas is no more than w, w≥1; the rectangular quartering refers to dividing the rectangular area into four rectangular areas of the same size; the leaf rectangular area refers to a rectangular area obtained by dividing the root rectangular area u times and not divided again, called a u-depth leaf rectangular area, u≥1; the rectangular area obtained by dividing the root rectangular area u times and divided again is called a u-depth branch rectangular area;

[0016] The data format of the quadtree root-branch-leaf is stored as follows: the two-dimensional points contained in some edges of the leaf rectangular area are stored in the leaf rectangular area; the u+1 depth leaf rectangular area or the u+1 depth branch rectangular area obtained by segmenting the u depth branch rectangular area is stored in the u depth branch rectangular area; the 1 depth leaf rectangular area or the 1 depth branch rectangular area obtained by segmenting the root rectangular area is stored in the root rectangular area;

[0017] The two-dimensional point contained in some edges of the u-depth leaf rectangular area refers to a two-dimensional point located in the leaf rectangular area and on some of its edges; when the partial edge of the leaf rectangular area refers to a two-dimensional point located on the common edge of the leaf rectangular area, the two-dimensional point can only be contained in one of the leaf rectangular areas.

[0018] Preferably, the composition relationship of the VGTP group is specifically as follows: num-1 VGTP units and corresponding num-1 attribute information formed by sequentially connecting num three-dimensional point groups in the VGTP group composition relationship constitute a VGTP group; num≥2;

[0019] The number of the three-dimensional point group is represented by arr or arr plus or minus a positive integer, and the three-dimensional point group contains three three-dimensional point references, and the three-dimensional point references are numbered 1, 2, and 3 respectively; the num-1 VGTP units are formed by sequentially connecting the num three-dimensional point groups in sequence, specifically: the three-dimensional point references in the three-dimensional point groups numbered arr and arr+1 are respectively formed into two triangle bases and two / three side faces according to the numbering sequence of the three-dimensional point groups, and the two / three side faces are enclosed into a VGTP unit; forming two / three side faces means sequentially selecting two three-dimensional point references in one three-dimensional point group and another three-dimensional point Two 3D point references with the same sequence number in the group are compared to form a quadrilateral side, a triangular side or no face, specifically: if the two selected 3D point references do not overlap with the two 3D point references with the same sequence number in another 3D point group, then a quadrilateral side is formed; if the two selected 3D point references and the two 3D point references with the same sequence number in another 3D point group have a pair of 3D point references with the same sequence number overlap, then a triangular side is formed; if the two selected 3D point references and the two 3D point references with the same sequence number in another 3D point group have two pairs of 3D point references with the same sequence number overlap, then no face is formed;

[0020] The starting value of arr is the number of the first three-dimensional point group. Each time a VGTP unit is formed, arr increases by 1.

[0021] The number of the num-1 attribute information is represented by pro or a positive integer plus or minus pro, and the starting value of pro is the number of the first group of attribute information; the attribute information corresponding to the VGTP unit in the VGTP group constitution relationship is specifically: each time the VGTP unit is constituted, the attribute information numbered pro is obtained, and then pro is incremented by 1;

[0022] The method of sequentially connecting num three-dimensional point groups to form num-1 VGTP units is called a VGTP intra-group unit formation method;

[0023] The 3D point references in the 3D point group of the VGTP group structure relationship correspond to three different 3D point data chains, and the 3D points in the 3D point data chain can be directly obtained through the 3D point references;

[0024] The storage order of the three-dimensional point groups in the constituent relationship of the VGTP group satisfies that the Z coordinate values ​​of the bottom surface of the unit constructed in sequence according to the storage order of the three-dimensional point groups are distributed from large to small.

[0025] Preferably, the sectioning process comprises the following steps:

[0026] Step 1: Get VGTP model data

[0027] Obtain all the data of the VGTP model and store it according to the basic data structure of the data storage method;

[0028] Step 2: Determine the VGTP group that needs to be dissected

[0029] Selecting a spatial sectioning plane, and determining the VGTP group to be sectioned according to the plane position relationship between the spatial sectioning plane and the rectangular area and the spatial relationship between the VGTP groups;

[0030] Step 3, sectioning the VGTP group

[0031] Obtain the set of VGTP groups to be sectioned and the spatial section plane in step 2, and adjust the composition relationship of the root 2D point data chain, the 3D point data chain and the VGTP group according to the intersection relationship between each VGTP group to be sectioned and the spatial section plane.

[0032] Preferably, the spatial sectioning surface is a group of closed surfaces composed of multiple continuous spatial planes; the spatial planes satisfy the requirement that each spatial plane is an arbitrary polygonal spatial plane with a finite area, and each edge of each spatial plane is a common edge of other spatial planes, and the spatial planes are called sectioning sub-surfaces; the closure means that the spatial sectioning surface itself can enclose a complete closed space, and the part of the VGTP model located in the closed space is the part that needs to be excavated.

[0033] Preferably, step 2 specifically includes the following steps:

[0034] Step 2.1, projecting multiple cutting sub-surfaces constituting the spatial cutting surface onto the same horizontal plane along the vertical direction to obtain multiple horizontal projection planes, and at the same time calculating the union of the multiple horizontal projection planes after projection according to Boolean operation, and finally obtaining a polygonal horizontal plane, which is called the cutting projection plane; the cutting projection plane is a two-dimensional polygonal plane without a Z coordinate value;

[0035] Step 2.2, searching according to the quadtree structure to screen out all leaf rectangular areas intersecting with the section projection plane, includes the following steps:

[0036] Step 2.2.1, determine whether the cutting projection surface intersects with the root rectangular area; if not, end the cutting process and keep all the data of the VGTP model unchanged; if intersecting, set u=1, and set the search range to the root rectangular area, and execute step 2.2.2;

[0037] Step 2.2.2, determine the u-depth branch rectangular area or u-depth leaf rectangular area intersecting the section projection plane in the rectangular area stored corresponding to the search range; record the u-depth leaf rectangular area intersecting the section projection plane as the intersecting leaf rectangular area; reset the search range to the u-depth branch rectangular area intersecting the section projection plane; set u=u+1, and repeat step 2.2.2 until no branch rectangular area in the rectangular area stored corresponding to the search range intersects the section projection plane;

[0038] The intersecting leaf rectangular areas recorded in step 2.2.2 are all the leaf rectangular areas that intersect with the section projection surface obtained by the final screening in step 2.2;

[0039] The intersection with the cut projection plane means that the cut projection plane and the rectangular area can obtain a surface with an area greater than zero by calculating the intersection according to Boolean operation;

[0040] Step 2.3, obtaining all the corresponding two-dimensional points stored in all leaf rectangular regions intersecting with the section projection plane in step 2.2, and recording them as possible intersecting two-dimensional points;

[0041] Step 2.4, obtaining all 3D point data chains corresponding to the possible intersecting 2D points, and obtaining the VGTP group generated by referencing the 3D points in the 3D point data chains according to the 3D point data chains, and storing them in the possible intersecting VGTP group set;

[0042] Step 2.5, determine whether each VGTP group in the set of possible intersecting VGTP groups intersects with the spatial section plane one by one in space, record all VGTP groups that intersect with the spatial section plane as VGTP groups to be sectioned, and put them into the same set, called the set of VGTP groups to be sectioned.

[0043] Preferably, step 3 specifically includes the following steps:

[0044] Step 3.1, selecting a VGTP group from the set of VGTP groups to be sectioned as the VGTP group to be sectioned, reading the composition relationship of the VGTP group to be sectioned and the three 3D point data chains where the 3D points referenced by it are located; reading the spatial sectioning plane;

[0045] Step 3.2, calculating the intersection surface between each sectioning sub-surface in the spatial sectioning surface and each VGTP unit in the VGTP group; the intersection surface is the part of the sectioning sub-surface located in the VGTP unit, which can be any polygonal spatial plane, called a sub-intersection surface;

[0046] Step 3.3, obtaining the unit bottom surface with the largest Z coordinate value in the VGTP group to be sectioned, projecting all sub-intersecting surfaces along the vertical direction to the unit bottom surface, and obtaining projection traces and trace points; the projection traces are the edges in the projection surface of the sub-intersecting surfaces that do not completely or partially overlap with the edges of the projected unit bottom surface; the trace points include the endpoints of the traces and the intersection points of the traces;

[0047] Step 3.4, adding a new trace line in the projected unit bottom surface, all trace lines including the new trace line can divide the projected unit bottom surface into k triangular sub-surfaces; the endpoints of the newly added trace line are trace points or vertices of the projected unit bottom surface; the newly added trace line does not intersect with the existing trace line;

[0048] Step 3.5, generating two-dimensional points with the same number as the trace points according to the coordinate values ​​of the trace points, specifically extracting the X coordinate value and Y coordinate value of each trace point as the X coordinate value and Y coordinate value of the newly generated two-dimensional point; all the two-dimensional points newly generated by the trace points are called the to-be-added two-dimensional points, and the number is recorded as g;

[0049] According to the number of the two-dimensional points to be added, g new three-dimensional point data chains are generated, and stored in one-to-one correspondence with each of the two-dimensional points to be added, and the corresponding storage relationship satisfies the corresponding storage relationship between the two-dimensional points and the three-dimensional point data chains in the root two-dimensional point data chain of the data basic structure of the data storage method; the three-dimensional point Z coordinate value of the first three-dimensional point of the g new three-dimensional point data chains is the Z coordinate value of the trace point of the two-dimensional point to be added corresponding to the generation of the new three-dimensional point data chain, and the three-dimensional point Z coordinate values ​​of the remaining three-dimensional points of the g new three-dimensional point data chains are to be determined by simulated projection;

[0050] Add k new VGTP groups to constitute a relationship; the first three-dimensional point group in the new k VGTP groups to constitute a relationship meets the requirements: the k triangular faces constituted by the three three-dimensional point references in the first three-dimensional point group in each new VGTP group completely overlap with the k triangular sub-faces described in step 3.4 in a one-to-one correspondence; the three three-dimensional point references in the first three-dimensional point group in each new VGTP group are all referenced from g new three-dimensional point data chains and the first three-dimensional point in the three three-dimensional point data chains read in step 3.1; the remaining three-dimensional point groups and attribute information of the new VGTP group to be simulated projection and volume inclusion relationship determination;

[0051] Step 3.6, carrying out the simulated projection described in step 3.5, specifically includes the following steps:

[0052] Step 3.6.1, obtain g newly added 3D point data chains and the first 3D point in the three 3D point data chains read in step 3.1, which is called the starting simulation projection point; successively project the starting simulation projection point to the simulated projection surface along the vertical direction; the simulated projection surface includes the unit bottom surface of the VGTP group to be cut obtained in step 3.1 except the unit bottom surface with the largest Z coordinate value and the sub-intersecting surface described in step 3.2;

[0053] In the process of successive projection, a new 3D point is added to the 3D point data chain or the new 3D point data chain where the starting simulated projection point of the successful projection is located, and the 3D point Z coordinate value of the new point is the Z coordinate value obtained during the successful projection; the successful projection means that a unique solution can be obtained within or on the edge of the simulated projection surface during the projection process;

[0054] In the process of successive projection, when a 3D point data chain or a newly added 3D point in a newly added 3D point data chain has three different 3D point data chains or a newly added 3D point in each of the newly added 3D point data chains satisfies the 3D point group constitution relationship, a new 3D point group is added to the corresponding newly added VGTP group constitution relationship;

[0055] The three-dimensional point group composition relationship satisfies that three different three-dimensional point data chains or newly added three-dimensional point data chains all add a three-dimensional point in the same projection process, and the three corresponding starting simulated projection points are simultaneously referenced by the first three-dimensional point group in the same newly added VGTP group composition relationship described in step 3.5; the newly added three-dimensional point group in the corresponding newly added VGTP group composition relationship refers to the reference of the three newly added three-dimensional points that satisfy the three-dimensional point group composition relationship according to the reference serial number of the first three-dimensional point group in the newly added VGTP group composition relationship of the three starting simulated projection points;

[0056] Step 3.6.2, obtaining the 3D point data chain or the newly added 3D point data chain in step 3.6.1, obtaining the points with the same Z coordinate values ​​of the 3D points through one-to-one comparison, merging them into one point, and pointing the reference relationship of the merged point to the merged point;

[0057] The merging in step 3.6.2 needs to be merged according to the storage sequence number of the merged point in the 3D point data chain or the newly added 3D point data chain. Specifically, only the merged point with the smallest storage sequence number is retained as the merging point, and the storage address is ensured not to change when the merged point with the smallest storage sequence number is changed to the merging point.

[0058] Step 3.6.3, obtaining the newly added VGTP group composition relationship after executing step 3.6.2, adjusting the storage order of the three-dimensional point groups in each newly added VGTP group, so that the storage order of the three-dimensional point groups in each newly added VGTP group composition relationship after adjustment satisfies that the Z coordinate values ​​of the bottom surface of the unit constructed in sequence according to the storage order of the three-dimensional point groups obey the distribution from large to small;

[0059] Step 3.7, determining the attribute information in the newly added VGTP group composition relationship according to the body inclusion relationship described in step 3.5, specifically:

[0060] Obtain the three-dimensional point group in the newly added VGTP group composition relationship described in step 3.6.3, and construct VGTP units in sequence according to the unit composition method within the VGTP group. Each time a VGTP unit is constructed, determine the spatial inclusion relationship between the newly constructed VGTP unit and the VGTP unit in the VGTP group to be cut described in step 3.1 and the spatial cutting surface, and determine the attribute information in the newly added VGTP group composition relationship;

[0061] The determining of the attribute information through the spatial inclusion relationship is specifically as follows: if the newly constructed VGTP unit of the newly added VGTP group composition relationship is completely located in a VGTP unit in the VGTP group to be sectioned and is not located in the spatial sectioning plane, then a new attribute information is added to the newly added VGTP group composition relationship, and the newly added attribute information is the attribute information of the VGTP unit in the VGTP group to be sectioned; if the newly constructed VGTP unit of the newly added VGTP group composition relationship is completely located in the closed space of the spatial sectioning plane, then a new attribute information is added to the newly added VGTP group composition relationship, and the attribute information is NULL;

[0062] Step 3.8, merge the three-dimensional point groups corresponding to NULL attribute information in the composition relationship of the VGTP group to be added, and make a deletion judgment, specifically:

[0063] Step 3.8.1, determine whether there is NULL attribute information with a continuous number in the newly added VGTP group composition relationship, if so, read the starting number proDS and the ending number proDE of the continuous number; read the first three-dimensional point group number arrS and the first attribute information number proS in the newly added VGTP group composition relationship;

[0064] Step 3.8.2, delete the attribute information numbered from proDS+1 to proDE, and delete the three-dimensional point group numbered from arrS+ to arrS+;

[0065] Step 3.8.3, after executing step 3.8.2 for all newly added VGTP group composition relationships, determine whether the attribute information with the largest or smallest number is NULL, and perform the deletion operation based on the determination result, specifically: if the newly added VGTP group composition relationship has only one set of attribute information and it is NULL, delete the newly added VGTP group composition relationship; if the attribute information in the newly added VGTP group composition relationship is greater than one set, and the attribute information with the largest number is NULL, delete the attribute information and three-dimensional point group with the largest number in the newly added VGTP group composition relationship; if the attribute information in the newly added VGTP group composition relationship is greater than one set, and the attribute information with the smallest number is NULL, delete the attribute information and three-dimensional point group with the smallest number in the newly added VGTP group composition relationship;

[0066] Step 3.8.4, renumbering the remaining three-dimensional point groups and attribute information in the newly added VGTP group composition relationship, requiring that the size relationship of the renumbered three-dimensional point groups and attribute information numbers remains unchanged and satisfies an arithmetic progression with a tolerance of one;

[0067] Step 3.8.5, search the g newly added 3D point data chains, and remove the 3D points that are not referenced by the newly added VGTP group composition relationship from the corresponding newly added 3D point data chains. If all the 3D points in the newly added 3D point data chain are removed, delete the newly added 3D point data chain and delete the corresponding 2D points to be added at the same time;

[0068] Step 3.8.6, adding the two-dimensional points to be added generated during the execution of steps 3.1-3.8 to the set of two-dimensional points added during the sectioning; adding the new VGTP group composition relationship generated during the execution of steps 3.1-3.8 to the set of new VGTP group composition relationship during the sectioning;

[0069] Step 3.9, performing steps 3.1-3.8 on the remaining VGTP groups to be dissected in the set of VGTP groups to be dissected described in step 2;

[0070] Step 3.10, obtaining the 3D point data chain containing the 3D points referenced by all the VGTP groups to be sectioned in the set of VGTP groups to be sectioned described in step 2, and removing the 3D points referenced by the newly added VGTP group constituent relationships in the set of newly added VGTP groups that have not been sectioned. If all the 3D points in the 3D point data chain are removed, then delete the 3D point data chain, and at the same time delete the 2D points in the corresponding root 2D point data chain;

[0071] Step 3.11, all the newly added two-dimensional points in the set of newly added two-dimensional points are stored in the root two-dimensional point data chain, and the two-dimensional points to be added are stored in the corresponding leaf rectangular areas according to their positions; the original leaf rectangular area to which the two-dimensional points to be added are further divided into four equal parts until the final leaf rectangular area contains at most w two-dimensional points, w ≥ 1, and the re-divided area is renamed according to the quadtree naming rule;

[0072] Step 3.12, deleting the composition relationship of all VGTP groups to be dissected in the set of VGTP groups to be dissected described in step 2.

[0073] Preferably, the rectangular area is recorded and stored using a two-dimensional rectangular plane without a Z coordinate value.

[0074] Preferably, the two-dimensional points in the root two-dimensional point data chain will increase or decrease during the sectioning process; and the corresponding two-dimensional points stored in the leaf rectangular area will change accordingly with the increase or decrease of the root two-dimensional point data chain.

[0075] Preferably, the Z coordinate value of the unit bottom surface is the Z coordinate value of the centroid point of the unit bottom surface, that is, the geometric center point.

[0076] The advantages of the present invention are:

[0077] (1) After the present invention establishes a model composed entirely of generalized triangular prism units with vertical side edges through spatial interpolation of drilling data, a topological relationship between the generalized triangular prism units with vertical side edges and their unit vertices is constructed, and at the same time, references to unit vertices and plane points are established based on the planar position relationship of the unit vertices, and the plane points are stored in a quadtree structure; during spatial sectioning calculation, the quadtree structure is used to retrieve the plane points included in the sectioned projection surface, and then the units to be sectioned are quickly determined by referencing the unit vertices and units of the included plane points, thereby achieving the effects of fast retrieval and storage saving.

[0078] (2) The present invention uses the coordinate relationship of the vertices of the generalized triangular prism (VGTP) unit with vertical side edges to uniformly store three-dimensional points with the same X and Y coordinate values ​​through corresponding two-dimensional points, thereby saving storage space for model data.

[0079] (3) The present invention stores two-dimensional points through a quadtree data structure and searches according to the quadtree during spatial sectioning calculations, which can effectively improve the efficiency of model spatial sectioning calculations.

[0080] (4) In the process of model space sectioning, the present invention only involves the data types of the root two-dimensional point data chain, the three-dimensional point data chain and the constituent relationship of the VGTP group in the basic data structure, in addition to the data storage structures of conventional points, lines and surfaces, so that the model calculation is stable and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] Figure 1 Schematic diagram of the geometry of the VGTP group in this embodiment.

[0082] Figure 2 Schematic diagram of the geometric sectioning of the VGTP group in the first embodiment of the present invention, wherein: (a) is a schematic diagram of the positional relationship between the VGTP group to be sectioned and the spatial sectioning plane in the first embodiment of the present invention; (b) is a schematic diagram of the spatial sectioning plane dividing the VGTP group to be sectioned in the first embodiment of the present invention.

[0083] Figure 3 Schematic diagram of the geometric sectioning of the VGTP group of the second embodiment, wherein: (a) is a schematic diagram of the positional relationship between the VGTP group to be sectioned and the spatial sectioning plane of the second embodiment; (b) and (c) are schematic diagrams of dividing the VGTP group to be sectioned by the spatial sectioning plane of the second embodiment.

[0084] Figure 4 This is a geometric diagram of the root two-dimensional point data link quadtree storage structure of this embodiment.

[0085] Figure 5 This is a schematic diagram of the data structure of the root two-dimensional point data link quadtree data storage in this embodiment.

[0086] Figure 6Schematic diagram of the composition relationship of the VGTP group to be cut in this embodiment and its corresponding three-dimensional point data chain and two-dimensional point data storage structure, wherein: (a) is a schematic diagram of the three-dimensional point data chain and two-dimensional point data storage structure corresponding to the composition relationship of the VGTP group to be cut in this embodiment; (b) is a schematic diagram of the data storage structure of the composition relationship of the VGTP group to be cut in this embodiment.

[0087] Figure 7 This is a schematic diagram of the newly added VGTP group composition relationship and its corresponding three-dimensional point data chain and two-dimensional point data storage structure of this embodiment, wherein: (a) is a schematic diagram of the three-dimensional point data chain and two-dimensional point data storage structure corresponding to the newly added VGTP group composition relationship of this embodiment; (b) is a schematic diagram of the data storage structure of the newly added VGTP group composition relationship of this embodiment.

[0088] Figure 8 This is a schematic diagram of the newly added VGTP group composition relationship and its corresponding three-dimensional point data chain and two-dimensional point data storage structure of the second embodiment, wherein: (a) is a schematic diagram of the three-dimensional point data chain and two-dimensional point data storage structure corresponding to the newly added VGTP group composition relationship of the second embodiment; (b) is a schematic diagram of the data storage structure of the newly added VGTP group composition relationship of the second embodiment.

[0089] The reference numerals are as follows:

[0090] 1. Unit vertex; 2. Unit bottom surface; 3. Attribute information; 4. 3D point group; 5. 3D point data link; 6. 3D point reference; 7. 2D point; 8. 2D point X coordinate value; 9. 2D point Y coordinate value; 10. 3D point; 11. 2D point X coordinate value reference; 12. 2D point Y coordinate value reference; 13. 3D point Z coordinate value; 14. 2D point to be added; 15. Added 3D point data link; 16. Added VGTP group composition relationship; 17. Sectioning projection surface; 18. Spatial sectioning surface. DETAILED DESCRIPTION

[0091] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0092] In the present invention, the expression form of the VGTP unit is ABD-A'B'D', wherein A, B, D, A', B' and D' are the unit vertices 1 of the VGTP unit; the expression form of the three-dimensional point group 4 in the embodiment is (A, B, D), wherein A, B and D are three-dimensional point references 6; all faces, lines and edges in the embodiment are expressed through their vertices.

[0093] Example 1.

[0094] The present invention provides a data storage method for cutting a generalized triangular prism model with vertical side edges, wherein the generalized triangular prism model with vertical side edges (VGTP) is composed of a plurality of VGTP groups that are adjacent in space.

[0095] like Figure 1 As shown, the VGTP group includes three VGTP units and their corresponding attribute information 3; the three VGTP units are ABD-A'BD, A'BD-A'B"D" and A'B"D"-A"'B"'D"'; the attribute information 3 corresponding to the VGTP unit is formation attribute information or NULL, wherein the VGTP unit corresponding to the formation attribute information is attached to the corresponding VGTP unit when it is generated, and the VGTP units with the same formation attributes constitute the same formation, and the VGTP unit corresponding to NULL indicates that it is not generated.

[0096] The space is represented by a (X, Y, Z) rectangular coordinate system, where Z represents the vertical direction and X and Y represent two horizontal directions.

[0097] like Figure 1 As shown, the VGTP unit is surrounded by two upper and lower triangular bases and two / three side surfaces; the upper and lower triangular bases are completely overlapped in the vertical projection, and the two triangular bases are called unit base 2, and the vertex of unit base 2 is called unit vertex 1; the two / three side surfaces are called unit side surfaces, and there are edges that intersect and completely overlap between any two of the unit side surfaces and are called side edges. In this embodiment, the two triangular bases of the VGTP unit ABD-A'BD are face ABD and face A'BD, the two side surfaces are face AA'D and face AA'B, and the side edge is edge AA'. The two triangular bases of the VGTP unit A'BD-A'B"D" are face A'BD and face A'B"D, and the three side surfaces are face A'DD", face A'BB" and face BDD"B, and the side edges include edge BB" and edge DD". The two triangular bases of the VGTP unit A'B"D"-A"'B"'D"' are face A'B"D" and face A"'B"'D"', the three side faces are face A'A"'B"B"', face A'A"'D"D"' and face B"D"D"'B"', and the side edges include edge A'A"', edge B"B"' and edge D"D"'.

[0098] The VGTP unit can be divided into three types according to the number of side edges, specifically: if the two side faces of the VGTP unit are two triangular side faces, then the VGTP unit only contains one vertical side edge, and the VGTP unit is called a VGTP unit with one side edge; if the three side faces of the VGTP unit are two triangular side faces and one quadrilateral side face, then the VGTP unit contains two vertical side edges, and the VGTP unit is called a VGTP unit with two side edges; if the three side faces of the VGTP unit are all quadrilateral side faces, then the VGTP unit contains three vertical side edges, and the VGTP unit is called a VGTP unit with three side edges.

[0099] The unit bottom surfaces 2 of all VGTP units contained in the VGTP group completely overlap when projected onto the same horizontal plane in the vertical direction; the unit side surfaces of all VGTP units contained in the VGTP group located on the same vertical spatial plane constitute the group side surfaces, which in this embodiment include surface AA"'B"'B, surface AA"'D"'D and surface BB"'D"'D.

[0100] The multiple VGTP groups that are adjacent in space refer to that there is at least one VGTP group adjacent to each VGTP group and that is spatially coplanar with the group; the spatial coplanarity refers to that two VGTP groups that are adjacent in space each have one group side surface that completely overlaps or partially overlaps.

[0101] by Figure 2 Taking (b) as an example, a total of 5 VGTP units A"'op-abc, abc-A'de, A'de-A'fg, A'fg-jhi, and jhi-Akm form a VGTP group 1. This VGTP group 1 has a VGTP group 2 that is spatially coplanar (that is, an adjacent surface) with it. This VGTP group 2 is a VGTP group 2 composed of three VGTP units, opD"'-deD", deD"-fgD, and fgD-kmD. These two VGTP groups have a completely overlapping adjacent surface, which is opmk, which is the spatial coplanarity described in the present invention. Of course, there are other situations. For example, the VGTP units abc-A'de, A'de-A'fg, and A'fg-jhi are removed, that is, the two VGTP units A"'op-abc and jhi-Akm form a VGTP group 3, then its group side surfaces opcb and himk partially overlap with the group side surface opmk of VGTP group 2.

[0102] The basic data structure of the data storage method is composed of a root two-dimensional point data chain, n three-dimensional point data chains 5 and a plurality of VGTP group constituting relationships.

[0103] like Figure 5As shown, the root two-dimensional point data chain includes n non-repeating two-dimensional points 7; the root two-dimensional point data chain satisfies that all the two-dimensional points 7 obtained after the two-dimensional deduplication conversion of all the unit vertices 1 in the VGTP model coincide with all the two-dimensional points 7 in the root two-dimensional point data chain; the two-dimensional deduplication conversion is to remove the Z coordinate values ​​in the spatial coordinates of all the unit vertices 1 and convert them into two-dimensional points 7, and merge the repeated two-dimensional points 7 into one; the two-dimensional point 7 in the root two-dimensional point data chain includes a two-dimensional point X coordinate value 8 and a two-dimensional point Y coordinate value 9, and the data type is floating point.

[0104] like Figure 4 and 5 As shown, the root two-dimensional point data link is stored in a quadtree root-branch-leaf data format according to the plane position of the two-dimensional point 7; the quadtree root-branch-leaf data format is:

[0105] A rectangular area PQCR on a plane whose edges include all the two-dimensional points 7 in the root two-dimensional point data chain is called the root rectangular area; the edge inclusion means that all the two-dimensional points 7 in the root two-dimensional point data chain are located in or on the edge of the root rectangular area PQCR.

[0106] The root rectangular area PQCR and the rectangular areas formed after the root rectangular area is divided are repeatedly divided in the form of rectangular quartering until the number of two-dimensional points 7 contained in some edges of all the leaf rectangular areas is no more than w (w≥1); the rectangular quartering refers to dividing the rectangular area into four rectangular areas of the same size; the leaf rectangular area refers to a rectangular area obtained by dividing the root rectangular area u times (u≥1) and not divided again, called a u-depth leaf rectangular area, and this embodiment includes 1-depth leaf rectangular areas PEHO, EQFO, HOGR and 2-depth leaf rectangular areas OKIJ, KFLI, ILCM, JIMG; the rectangular area obtained by dividing the root rectangular area u times and divided again is called a u-depth branch rectangular area, and this embodiment is a 1-depth branch rectangular area OFCG.

[0107] In this embodiment, the data format of the root-branch-leaf of a quadtree is used for storage, and the data is divided into four equal parts of a rectangle by a horizontal line and a vertical line, which is more convenient. Of course, the data format of the root-branch-leaf of a multi-branch tree such as a binary, tri-branch, or quintuple can also be used for storage, that is, the data is divided into two equal parts, three equal parts, five equal parts, or other equal parts.

[0108] Furthermore, the naming rule of the u-depth leaf rectangular region and the u-depth branch rectangular region is called a quadtree naming rule.

[0109] Furthermore, the two-dimensional point 7 contained in some edges within the u-depth leaf rectangular area refers to the two-dimensional point 7 located within the leaf rectangular area and on some of its edges; when the partial edge of the leaf rectangular area refers to the two-dimensional point 7 located on the common edge of the leaf rectangular area, the two-dimensional point 7 can only be contained in one of the leaf rectangular areas.

[0110] Furthermore, if Figure 4 As shown, the data format of the quadtree root-branch-leaf is stored as follows: the two-dimensional point 7 contained in some edges in the leaf rectangular area is stored in the leaf rectangular area; the u+1 depth leaf rectangular area or the u+1 depth branch rectangular area obtained by dividing the u depth branch rectangular area is stored in the u depth branch rectangular area, and the 2 depth leaf rectangular areas OKIJ, KFLI, ILCM, and JIMG of this embodiment are stored in the 1 depth branch rectangular area OFCG; the 1 depth leaf rectangular area or the 1 depth branch rectangular area obtained by dividing the root rectangular area is stored in the root rectangular area, and the 1 depth leaf rectangular area PEHO, EQFO, HOGR and the 1 depth branch rectangular area OFCG of this embodiment are stored in the root rectangular area PQCR.

[0111] Furthermore, all rectangular areas are recorded and stored using a two-dimensional rectangular plane without a Z coordinate value.

[0112] Furthermore, the two-dimensional points 7 in the root two-dimensional point data chain may increase or decrease during the sectioning process; the corresponding two-dimensional points 7 stored in the leaf rectangular area may change accordingly with the increase or decrease of the root two-dimensional point data chain.

[0113] The n of the n three-dimensional point data chains 5 is equal to the number of all two-dimensional points 7, and each three-dimensional point data chain 5 corresponds to a two-dimensional point 7 in the root two-dimensional point data chain.

[0114] Figure 6 and Figure 7 They are respectively the structural relationship of the VGTP group to be sectioned and the newly added VGTP group and the schematic diagram of their corresponding three-dimensional point data chain and two-dimensional point data storage structure.

[0115] like Figure 6 (a) and Figure 7 As shown in (a), the 3D point 10 in the 3D point data chain 5 includes a 2D point X coordinate value reference 11, a 2D point Y coordinate value reference 12 and a 3D point Z coordinate value 13. The 2D point X coordinate value 8 and the 2D point Y coordinate value 9 of the 2D point 7 corresponding to the 3D point data chain 5 where the 3D point 10 is located can be obtained through the 2D point X coordinate value reference 11 and the 2D point Y coordinate value reference 12. The 3D point Z coordinate value 13 is floating point data.

[0116] Since the (X, Y) coordinates of many vertices of multiple VGTP units in the same VGTP unit group are the same, Figure 2Taking (b) as an example, A”'op-abc, abc-A'de, A'de-A'fg, A'fg-jhi, jhi-Akm, a total of 5 VGTP units form a VGTP group 1. The (X, Y) coordinate values ​​of the five unit vertices A”', a, A', j, A are the same. If we follow the conventional storage idea, that is, the (X, Y, Z) coordinate values ​​of the five unit vertices are stored using numbers respectively, then storing the coordinate values ​​of the five unit vertices will require 15 digits of hard disk storage space; since the present invention utilizes the data rules of the VGTP unit, only the (X, Y, Z) coordinate values ​​of one unit vertex and the Z coordinate values ​​of the remaining unit vertices need to be stored, and only 7 digits need to be stored, and then these 7 digits need to be arranged according to our specific storage rules.

[0117] like Figure 6 (b) and Figure 7 As shown in (b), the composition relationship of the VGTP group includes all information for generating all VGTP units in the VGTP group and their corresponding attribute information 3, specifically: num-1 VGTP units are sequentially connected by num (num≥2) three-dimensional point groups 4 in the VGTP group composition relationship, and num-1 attribute information 3 are correspondingly assigned to the num-1 VGTP units.

[0118] Furthermore, the data storage structure of the VGTP group composition relationship is num three-dimensional point groups 4 stored in sequence and num-1 attribute information 3 stored in sequence. That is, the VGTP group contains two types of information, one is used to construct the geometry of the VGTP unit, and the other is other attribute information corresponding to the VGTP unit, such as material information.

[0119] The numbering of the three-dimensional point group 4 is represented by arr or arr plus or minus a positive integer, and the three-dimensional point group 4 contains three three-dimensional point references 6, and the three-dimensional point references 6 have group numbers of 1, 2, and 3 respectively; the num-1 VGTP units are formed by sequentially connecting the num three-dimensional point groups 4, specifically: according to the numbering order of the three-dimensional point groups 4, the three-dimensional point references 6 in the three-dimensional point groups 4 numbered arr and arr+1 are respectively formed into two triangular bases and two / three side faces, and enclosed into a VGTP unit; forming two / three side faces means sequentially selecting two three-dimensional point references 6 in one three-dimensional point group 4 and another three-dimensional point group The two 3D point references 6 with the same sequence number in 4 are compared to form a quadrilateral side, a triangular side or no face, specifically: if the two selected 3D point references 6 do not overlap with the two 3D point references 6 with the same sequence number in another 3D point group 4, then a quadrilateral side is formed; if the two selected 3D point references 6 overlap with the two 3D point references 6 with the same sequence number in another 3D point group 4, then a triangular side is formed; if the two selected 3D point references 6 overlap with the two 3D point references 6 with the same sequence number in another 3D point group 4, then two pairs of 3D point references 6 with the same sequence number overlap, then no face is formed.

[0120] The starting value of arr is the serial number of the first three-dimensional point group 4, and arr increases by 1 each time a VGTP unit is constructed.

[0121] by Figure 6 (b) is taken as an example, 4 groups of 3D point groups 4 are connected in sequence to form 3 VGTP units, and the 4 groups of 3D point groups 4 are numbered 1 to 4. Specifically, according to the numbering order of the 3D point groups 4, the 3D point references 6 in the 3D point groups 4 numbered 1 and 2 respectively constitute the two triangular bases, namely, the surface A"'B"'D"' and the surface A'B"D", and the three quadrilateral sides, namely, the surface A'A"'B"B"', the surface A'A"'D"D"' and the surface B"D"D"'B"', and enclose them into a VGTP unit A'B"D"-A"'B"'D"'; then the 3D point references 6 in the 3D point groups 4 numbered 1 and 2 are connected in sequence to form the VGTP unit A'B"D"-A"'B"'D"'; then The three-dimensional point references 6 in the three-dimensional point groups 4 numbered 3 and 4 respectively constitute two triangular bases, namely, surface A'B"D" and surface A'BD, as well as two triangular side surfaces, namely, surface A'DD" and surface A'BB", and one quadrilateral side surface, namely, surface BDD"B", to enclose a VGTP unit A'BD-A'B"D"; then the three-dimensional point references 6 in the three-dimensional point groups 4 numbered 3 and 4 respectively constitute two triangular bases, namely, surface A'BD and surface ABD, as well as two triangular side surfaces, namely, surface AA'D and surface AA'B, to enclose a VGTP unit ABD-A'BD.

[0122] The method of sequentially connecting num three-dimensional point groups 4 to form num-1 VGTP units is called a VGTP intra-group unit formation method.

[0123] Furthermore, the 3D point references 6 in the 3D point group 4 of the VGTP group constitution relationship correspond to three different 3D point data chains 5 , and the 3D point 10 in the 3D point data chain 5 can be directly obtained through the 3D point references 6 .

[0124] The numbering of the num-1 attribute information 3 is represented by pro or a positive integer plus or minus pro, and the starting value of pro is the numbering of the first group of attribute information 3; the attribute information 3 corresponding to the VGTP unit in the VGTP group composition relationship is specifically: each time the VGTP unit is composed, it obtains the attribute information 3 numbered pro, and then pro is incremented by 1.

[0125] by Figure 6 Taking (b) as an example, the attribute information 3 corresponding to the VGTP unit in the VGTP group composition relationship is specifically: the attribute information 3 corresponding to the sequentially constructed VGTP units A'B"D"-A"'B"'D"', A'BD-A'B"D" and ABD-A'BD are Property1, Property2 and Property3 respectively.

[0126] Furthermore, the three-dimensional point group 4 and the attribute information 3 are both numbered according to an arithmetic progression with a common difference of 1.

[0127] Furthermore, if Figure 1 and Figure 6 As shown in (b), the storage order of the three-dimensional point group 4 in the composition relationship of the VGTP group satisfies that the Z coordinate values ​​of the unit bottom surface 2 constructed in sequence according to the storage order of the three-dimensional point group 4 obey the distribution from large to small.

[0128] Figure 2 is a schematic diagram of a geometric cross-section of a VGTP group of this embodiment; Figure 4 This is a geometric diagram of the root two-dimensional point data link quadtree storage structure of this embodiment; Figure 5 This is a schematic diagram of the data structure of the root two-dimensional point data link quadtree data storage of this embodiment; Figure 6 This is a schematic diagram of the composition relationship of the VGTP group to be cut in this embodiment and its corresponding three-dimensional point data chain and two-dimensional point data storage structure; Figure 7 Schematic diagram of the newly added VGTP group composition relationship and its corresponding three-dimensional point data chain and two-dimensional point data storage structure of this embodiment.

[0129] like Figure 2 , Figures 4 to 7 As shown, the cutting process of the data storage method for cutting a generalized triangular prism model with vertical side edges includes the following steps:

[0130] Step 1: Get VGTP model data

[0131] Obtain all the data of the VGTP model and store it according to the basic data structure of the data storage method;

[0132] Step 2: Determine the VGTP group that needs to be dissected

[0133] Selecting a spatial sectioning plane 18, and determining the VGTP group to be sectioned according to the plane position relationship between the spatial sectioning plane 18 and the rectangular area and the spatial relationship between the VGTP groups;

[0134] The space section plane 18 is a closed surface composed of a plurality of continuous space planes; the space planes satisfy that each space plane is an arbitrary polygonal space plane with a finite area, and each edge of each space plane is a common edge of other space planes, and the space plane is called a sectioning sub-plane; the closure means that the space section plane 18 itself can enclose a complete closed space, and the part of the VGTP model located in the closed space is the part that needs to be excavated;

[0135] The plane position relationship between the spatial section plane 18 and the rectangular area is searched according to the quadtree data structure, including the following steps:

[0136] Step 2.1, such as Figure 4 As shown, multiple cutting sub-surfaces constituting the space cutting surface 18 are projected onto the same horizontal plane along the vertical direction to obtain multiple horizontal projection planes, and the multiple horizontal projection planes after projection are unioned according to Boolean operation to finally obtain a polygonal horizontal plane, which is called the cutting projection plane 17; the cutting projection plane 17 is a two-dimensional polygonal plane without a Z coordinate value;

[0137] Step 2.2, searching according to the quadtree structure to screen out all leaf rectangular areas intersecting with the section projection plane 17, includes the following steps:

[0138] Step 2.2.1, as Figure 4 As shown, determine whether the cutting projection plane 17 intersects with the root rectangular region PQCR; if not, end the cutting process and keep all the data of the VGTP model unchanged; if intersecting, set u=1, and set the search range to the root rectangular region PQCR, and execute step 2.2.2;

[0139] Step 2.2.2, as Figure 4As shown, determine the u-depth branch rectangular area or u-depth leaf rectangular area intersecting with the section projection plane 17 in the rectangular area stored corresponding to the search range; record the u-depth leaf rectangular area intersecting with the section projection plane 17 as the intersecting leaf rectangular area; reset the search range to the u-depth branch rectangular area intersecting with the section projection plane 17; set u=u+1, and repeat step 2.2.2 until there is no branch rectangular area in the rectangular area stored corresponding to the search range that intersects with the section projection plane 17;

[0140] Furthermore, the intersecting leaf rectangular areas recorded in step 2.2.2 are all leaf rectangular areas finally screened and obtained in step 2.2 and intersecting with the section projection plane 17;

[0141] Furthermore, the intersection with the cut projection plane 17 means that the cut projection plane 17 and the rectangular area can obtain a surface with an area greater than zero by calculating the intersection according to Boolean operation.

[0142] by Figure 4 For example, all leaf rectangular areas intersecting with the cut projection plane 17 are: 2-depth leaf rectangular area OKIJ and 2-depth leaf rectangular area KFLI;

[0143] Step 2.3, such as Figure 5 As shown, all the corresponding two-dimensional points 7 stored in all leaf rectangular regions intersecting with the section projection plane 17 in step 2.2 are obtained and recorded as possible intersecting two-dimensional points;

[0144] Step 2.4, obtaining all three-dimensional point data chains 5 corresponding to the possible intersecting two-dimensional points, and obtaining VGTP groups generated by referencing the three-dimensional points 10 therein according to all the three-dimensional point data chains 5, and storing them in a possible intersecting VGTP group set;

[0145] Step 2.5, spatially determine whether each VGTP group in the set of possible intersecting VGTP groups intersects with the spatial cutting plane 18 one by one, and record all VGTP groups intersecting with the spatial cutting plane 18 as VGTP groups that need to be cut and put them into the same set, which is called the set of VGTP groups to be cut;

[0146] Step 3, sectioning the VGTP group

[0147] Obtain the set of VGTP groups to be sectioned and the spatial section plane 18 in step 2, and adjust the composition relationship of the root two-dimensional point data chain, the three-dimensional point data chain 5 and the VGTP group through the intersection relationship between each VGTP group and the spatial section plane 18;

[0148] The adjustment comprises the following steps:

[0149] Step 3.1, such as Figure 2As shown, a VGTP group is selected from the set of VGTP groups to be dissected as the VGTP group to be dissected, such as Figure 5 As shown, the composition relationship of the VGTP group and the three 3D point data chains 5 where the referenced 3D point 10 is located are read; the space section plane 18 is read;

[0150] Step 3.2, such as Figure 2 As shown, the intersection surfaces of each sectioning sub-surface in the spatial sectioning surface 18 and each VGTP unit in the VGTP group are calculated, which in this embodiment are surface abc, surface bdec, surface dfge, surface fhig and surface jhi; the intersection surface is the part of the sectioning sub-surface located in the VGTP unit, which can be any polygonal spatial plane, called a sub-intersection surface;

[0151] Step 3.3, such as Figure 2 As shown, the unit bottom surface 2 with the largest Z coordinate value in the VGTP group to be sectioned is obtained, which is the surface A"'B"'D"' in this embodiment, and all sub-intersecting surfaces are projected along the vertical direction to the unit bottom surface 2 to obtain projection traces and trace points; the projection traces are the edges in the projection surface of the sub-intersecting surfaces that do not completely or partially overlap with the edges of the projected unit bottom surface 2; the trace points include the endpoints of the traces and the intersection points of the traces;

[0152] Step 3.4, such as Figure 2 As shown, a new trace is added to the bottom surface 2 of the projected unit, and all traces including the new trace can divide the bottom surface 2 of the projected unit into k triangular sub-surfaces; the endpoints of the newly added trace are trace points or vertices of the bottom surface 2 of the projected unit; the newly added trace does not intersect with the existing trace;

[0153] Step 3.5, such as Figure 7 As shown in (a), according to the coordinate values ​​of the trace points, two-dimensional points 7 with the same number as the trace points are generated, specifically, the X and Y coordinate values ​​of each trace point are extracted as the X and Y coordinate values ​​of the newly generated two-dimensional point 7; all the two-dimensional points 7 newly generated by the trace points are called the two-dimensional points to be added 14, which are (Xs1, Ys1) and (Xs2, Ys2) in this embodiment, and the number is recorded as g;

[0154] like Figure 7 As shown in (a), g new three-dimensional point data chains 15 are generated according to the number of the two-dimensional points 14 to be added, and are stored in a one-to-one correspondence with each of the two-dimensional points 14 to be added. The corresponding storage relationship satisfies the corresponding storage relationship between the two-dimensional point 7 and the three-dimensional point data chain 5 in the root two-dimensional point data chain of the data basic structure of the data storage method; the three-dimensional point Z coordinate value 13 of the first three-dimensional point 10 of the g new three-dimensional point data chains 15 is the Z coordinate value of the trace point of the two-dimensional point 14 to be added corresponding to the new three-dimensional point data chain 15, and the three-dimensional point Z coordinate values ​​13 of the remaining three-dimensional points 10 of the g new three-dimensional point data chains 15 are to be determined by simulated projection;

[0155] like Figure 2 and Figure 7 (b) As shown, k newly added VGTP groups constitute a relationship; the first group of three-dimensional point groups 4 in the said newly added k VGTP groups constitute a relationship, meeting the requirements: the k triangular faces formed by the three three-dimensional point references 6 in the first group of three-dimensional point groups 4 in each newly added VGTP group completely overlap with the k triangular sub-faces described in step 3.4 in a one-to-one correspondence; the three three-dimensional point references 6 in the first group of three-dimensional point groups 4 in each newly added VGTP group are all referenced from g newly added three-dimensional point data chains 15 and the first three-dimensional point 10 in the three three-dimensional point data chains 5 read in step 3.1; the remaining three-dimensional point groups 4 and attribute information 3 in the said newly added VGTP group constitute a relationship 16 to be simulated for projection and volume inclusion relationship determination;

[0156] Step 3.6, carrying out the simulated projection described in step 3.5, specifically includes the following steps:

[0157] Step 3.6.1, as Figure 2 and Figure 7 As shown, obtain g newly added 3D point data chains 15 and the first 3D point 10 in the three 3D point data chains 5 read in step 3.1, which is called the starting simulation projection point; successively project the starting simulation projection point to the simulated projection surface along the vertical direction; the simulated projection surface includes the unit bottom surface 2 except the unit bottom surface 2 with the largest Z coordinate value in the VGTP group to be cut obtained in step 3.1 and the sub-intersecting surface described in step 3.2;

[0158] Furthermore, in the process of successive projection, a three-dimensional point 10 is added to the three-dimensional point data chain 5 or the newly added three-dimensional point data chain 15 where the starting simulated projection point of the successful projection is located, and the three-dimensional point Z coordinate value 13 of the newly added point is the Z coordinate value obtained during the successful projection; the successful projection means that a unique solution can be obtained within or on the edge of the simulated projection surface during the projection process;

[0159] by Figure 2 For example, the simulated projection surface includes surface ABD, surface A'BD, surface A'B"D", surface abc, surface bdec, surface dfge, surface fhig and surface jhi. In the process of successive projection, the simulated projection surface ABD, surface A'BD and surface A'B"D" are projected, and all the starting simulated projection points can obtain a unique solution; in the process of successive projection, the starting simulated projection point A"', point o and point p are projected onto the simulated projection surface abc and surface jhi to obtain a unique solution; the simulated projection surface bdec, surface dfge and surface fhig cannot obtain a unique solution for all the starting simulated projection points;

[0160] Furthermore, in the process of successive projection, when a 3D point 10 is added to a 3D point data chain 5 or a newly added 3D point data chain 15, when there are three different 3D point data chains 5 or a newly added 3D point 10 in each of the newly added 3D point data chains 15 that satisfy the 3D point group composition relationship, a 3D point group 4 is added to the corresponding newly added VGTP group composition relationship 16;

[0161] The three-dimensional point group composition relationship satisfies that three three-dimensional point data chains 5 or newly added three-dimensional point data chains 15 each add a three-dimensional point 10 in the same projection process, and the three corresponding starting simulated projection points are simultaneously referenced by the first three-dimensional point group 4 in the same newly added VGTP group composition relationship 16 in step 3.5; the newly added three-dimensional point group 4 in the corresponding newly added VGTP group composition relationship 16 refers to the reference sequence of the first three-dimensional point group 4 in the newly added VGTP group composition relationship 16 of the three starting simulated projection points corresponding to the reference of the three newly added three-dimensional points 10 that satisfy the three-dimensional point group composition relationship;

[0162] like Figure 7 As shown, Figure 2 Taking the projection of all simulated projection points to the simulated projection surface abc as an example, the one 3D point data chain 5 where the starting simulated projection point A'', point o and point p are located and the two newly added 3D point data chains 15 each add a 3D point a, point b and point c in this projection process, and the three corresponding starting simulated projection points A'', point o and point p are simultaneously referenced by the first group of 3D point groups 4 in the same newly added VGTP group constituent relationship 16 in step 3.5, then point a, point b and point c satisfy the 3D point group constituent relationship; according to the reference serial numbers of the first group of 3D point groups 4 of the three starting simulated projection points A'', point o and point p in the newly added VGTP group constituent relationship 16, the three newly added 3D points a, point b and point c that satisfy the 3D point group constituent relationship are correspondingly referenced in the newly added 3D point group 4 of the newly added VGTP group constituent relationship 16;

[0163] Step 3.6.2, as Figure 2 As shown, the 3D point data chain 5 or the 3D point data chain 15 in which the newly added 3D point 10 is present in step 3.6.1 is obtained, and the points with the same 3D point Z coordinate values ​​13 are obtained by one-to-one comparison, and are merged into one point, and the reference relationship of the merged point is directed to the merged point;

[0164] Furthermore, the merging described in step 3.6.2 needs to be merged according to the storage sequence number of the merged point in the three-dimensional point data link 5 or the newly added three-dimensional point data link 15, specifically: only the merged point with the smallest storage sequence number is retained as the merging point, and it is ensured that the storage address does not change when the merged point with the smallest storage sequence number is changed to the merging point;

[0165] like Figure 7 As shown, Figure 2 Taking the newly added point successfully projected from the starting simulated projection point A'' to the simulated projection surface ABD as an example, during this projection process, a point equal to the 3D point Z coordinate value 13 of point A is successfully projected in the 3D point data chain 5 where the starting simulated projection point A'' is located, then the point is deleted and the 3D point group 4 constructed by referencing the point, point k and point m is modified to reference point A, point k and point m;

[0166] Step 3.6.3, obtaining the newly added VGTP group composition relationship 16 after executing step 3.6.2, adjusting the storage order of the three-dimensional point group 4 in each newly added VGTP group, so that the storage order of the three-dimensional point group 4 in each newly added VGTP group composition relationship 16 after adjustment satisfies that the Z coordinate value of the unit bottom surface 2 constructed in sequence according to the storage order of the three-dimensional point group 4 obeys the distribution from large to small;

[0167] Step 3.7, determining the attribute information 3 in the newly added VGTP group composition relationship 16 according to the body inclusion relationship described in step 3.5, specifically:

[0168] like Figure 2 As shown, the three-dimensional point group 4 in the newly added VGTP group composition relationship 16 described in step 3.6.3 is obtained, and the VGTP units are constructed in sequence according to the unit composition method within the VGTP group. Each time a VGTP unit is constructed, the spatial inclusion relationship between the newly constructed VGTP unit and the VGTP unit in the VGTP group to be cut described in step 3.1 and the spatial cutting surface 18 is determined to determine the attribute information 3 in the newly added VGTP group composition relationship 16;

[0169] Further, the determining of the attribute information 3 through the spatial inclusion relationship is specifically as follows: if the VGTP unit newly constructed by the newly added VGTP group composition relationship 16 is completely located in a VGTP unit in the VGTP group to be sectioned, and is not located in the spatial sectioning plane 18, then a new attribute information 3 is added to the newly added VGTP group composition relationship 16, and the newly added attribute information 3 is the attribute information 3 of the VGTP unit in the VGTP group to be sectioned; if the VGTP unit newly constructed by the newly added VGTP group composition relationship 16 is completely located in the closed space of the spatial sectioning plane 18, then a new attribute information 3 is added to the newly added VGTP group composition relationship 16, and the attribute information 3 is NULL;

[0170] by Figure 2Taking the newly added VGTP group constitution relationship 16 in which the reference point A"', point o and point p constitute the first three-dimensional point group 4 as an example, VGTP units abc-A"'op, A'de-abc, A'fg-A'de, jhi-A'fg and Akm-jhi are constructed in sequence according to the unit constitution method within the VGTP group, and each time the attribute information 3 of the VGTP unit abc-A"'op is determined to be the attribute information 3 of the VGTP unit A'B"D"-A"'B"'D"' according to the spatial inclusion relationship; the attribute information 3 of the VGTP units A'de-abc, A'fg-A'de and jhi-A'fg are all NULL; the attribute information 3 of the VGTP unit Akm-jhi is the attribute information 3 of the VGTP unit ABD-A'BD;

[0171] Step 3.8, such as Figure 2 As shown, the three-dimensional point group 4 corresponding to the attribute information 3 being NULL in the VGTP group composition relationship 16 to be added is merged, and a deletion judgment is performed, specifically:

[0172] Step 3.8.1, determine whether there is a NULL attribute information 3 with a continuous number in the newly added VGTP group composition relationship 16, if so, read the starting number proDS and the ending number proDE of the continuous number; read the first three-dimensional point group 4 number arrS and the first attribute information 3 number proS in the newly added VGTP group composition relationship 16;

[0173] Step 3.8.2, delete the attribute information 3 numbered from proDS+1 to proDE, and delete the three-dimensional point group 4 numbered from arrS+(proDS+1-proS) to arrS+(proDE-proS);

[0174] Step 3.8.3, after executing step 3.8.2 for all newly added VGTP group composition relationships 16, determine whether the attribute information 3 with the largest or smallest number is NULL, and perform the deletion operation according to the determination result, specifically: if the newly added VGTP group composition relationship 16 has only one group of attribute information 3 and it is NULL, then delete the newly added VGTP group composition relationship 16; if the attribute information 3 in the newly added VGTP group composition relationship 16 is greater than one group, and the attribute information 3 with the largest number is NULL, then delete the attribute information 3 with the largest number and the three-dimensional point group 4 in the newly added VGTP group composition relationship 16; if the attribute information 3 in the newly added VGTP group composition relationship 16 is greater than one group, and the attribute information 3 with the smallest number is NULL, then delete the attribute information 3 with the smallest number and the three-dimensional point group 4 in the newly added VGTP group composition relationship 16;

[0175] Step 3.8.4, renumbering the remaining three-dimensional point groups 4 and attribute information 3 in the newly added VGTP group composition relationship 16, requiring that the size relationship between the numbers of the three-dimensional point groups 4 and attribute information 3 after renumbering remains unchanged and satisfies an arithmetic progression with a tolerance of one;

[0176] Step 3.8.5, search the g newly added 3D point data chains 15, and remove the 3D points 10 that are not referenced by the newly added VGTP group composition relationship 16 from the corresponding newly added 3D point data chains 15. If all the 3D points 10 in the newly added 3D point data chain 15 are removed, delete the newly added 3D point data chain 15, and delete the corresponding 2D point 14 to be added;

[0177] Step 3.8.6, adding the two-dimensional points to be added 14 generated during the execution of steps 3.1-3.8 to the set of two-dimensional points added during the sectioning; adding the new VGTP group composition relationship 16 generated during the execution of steps 3.1-3.8 to the set of new VGTP group composition relationship during the sectioning;

[0178] by Figure 2 The result obtained by executing step 3.8 is shown in FIG. 16, which takes the newly added VGTP group constitution relation 16 of the first three-dimensional point group 4 as an example. Figure 7 ;

[0179] Step 3.9, performing steps 3.1-3.8 on the remaining VGTP groups to be dissected in the set of VGTP groups to be dissected described in step 2;

[0180] Step 3.10, obtaining the three-dimensional point data chain 5 where the three-dimensional point 10 referenced by all the VGTP groups to be sectioned in the set of VGTP groups to be sectioned described in step 2 is located, and removing the three-dimensional point 10 referenced by the newly added VGTP group constituent relationship 16 in the set of newly added VGTP groups to be sectioned that has not been sectioned. If all the three-dimensional points 10 in the three-dimensional point data chain 5 are removed, then delete the three-dimensional point data chain 5, and at the same time delete the two-dimensional point 7 in the corresponding root two-dimensional point data chain;

[0181] Step 3.11, all the newly added two-dimensional points in the set of newly added two-dimensional points are stored in the root two-dimensional point data chain, and the two-dimensional points 14 to be added are stored in the corresponding leaf rectangular area according to the position of the two-dimensional point 14 to be added; the original leaf rectangular area to which the two-dimensional point 14 to be added is further divided into four equal parts, until the final leaf rectangular area contains at most w (w≥1) two-dimensional points 7, and the re-divided area is renamed according to the quadtree naming rule;

[0182] Step 3.12, deleting the composition relationship of all VGTP groups to be dissected in the set of VGTP groups to be dissected described in step 2;

[0183] Furthermore, the Z coordinate value of the unit bottom surface 2 is the Z coordinate value of the centroid point of the unit bottom surface 2 .

[0184] Example 2.

[0185] like Figure 3 and Figure 8 As shown, the difference from Example 1 is that Example 2 uses another set of spatial cutting planes 18 to cut the VGTP group to be cut.

[0186] like Figure 3 As shown, when step 3.2 is executed in this embodiment, the intersection surfaces of each sectioning sub-surface in the obtained spatial sectioning surface 18 and each VGTP unit in the VGTP group are surface abcd, surface dcef, surface fegh, surface bijc, surface cjke and surface ekmg.

[0187] When step 3.8 is executed in this embodiment, if the newly added VGTP group composition relationship 16 in which the first three-dimensional point group 4 is (A', a, b), (A', b, i) has only one set of attribute information 3 as NULL, then the newly added VGTP group composition relationship 16 in which the first three-dimensional point group 4 is (A', a, b), (A', b, i) is deleted; the newly added VGTP group composition relationship 16 in which the first three-dimensional point group 4 is (A', a, b), (A', b, i) is deleted; of If the attribute information 3 in the newly added VGTP group composition relationship 16 is greater than one group, and the attribute information 3 with the largest number is NULL, then delete the attribute information 3 with the largest number in the newly added VGTP group composition relationship 16 and the three-dimensional point group 4; point a, point b, point i, point point point point point and Point If there are 3D points 10 not referenced by the newly added VGTP group composition relationship 16 in the newly added 3D point data chain 15, these unreferenced 3D points 10 are removed from these newly added 3D point data chains 15. The result obtained after the VGTP group to be cut executes step 3.8 in this embodiment is as follows: Figure 8 shown.

[0188] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A data storage method for a generalized triangular prism model with vertical side edges, characterized in that: The generalized triangular prism with vertical side edges, i.e., the VGTP model, is composed of a plurality of VGTP groups that are adjacent in space; the VGTP group contains at least one VGTP unit and its corresponding attribute information (3); the VGTP unit is surrounded by two upper and lower triangular bases and two / three side faces; the upper and lower triangular bases are called unit bases (2), and the vertices of the unit bases (2) are called unit vertices (1); the two / three side faces are called unit side faces, and the edges that intersect and completely overlap in the unit side faces are called side edges; the unit bases (2) of all VGTP units contained in the VGTP group are completely overlapped when projected vertically onto the same horizontal plane; the unit side faces of all VGTP units contained in the VGTP group that are located on the same vertical spatial plane constitute the group side faces; the plurality of VGTP groups that are adjacent in space refer to that each VGTP group has at least one VGTP group in the same spatial plane coplanar with the VGTP group; the spatial coplanarity refers to that two VGTP groups that are adjacent in space each have one group side face that completely overlaps or partially overlaps; The basic data structure of the data storage method is composed of a root two-dimensional point data chain, n three-dimensional point data chains (5) and a plurality of VGTP group structure relationships; The root two-dimensional point data chain includes n non-repeating two-dimensional points (7), and the n non-repeating two-dimensional points (7) are all the two-dimensional points (7) obtained after all the unit vertices (1) in the VGTP model are transformed into two-dimensional points (7) according to two-dimensional deduplication conversion; the two-dimensional deduplication conversion is to remove the Z coordinate values ​​of all the unit vertices (1) and transform them into two-dimensional points (7), and merge the repeated two-dimensional points (7) into one; The n three-dimensional point data chains (5) correspond to n non-repeating two-dimensional points (7) in the root two-dimensional point data chain respectively; the three-dimensional point (10) in the three-dimensional point data chain (5) comprises a two-dimensional point X coordinate value reference (11), a two-dimensional point Y coordinate value reference (12) and a three-dimensional point Z coordinate value (13); the two-dimensional point X coordinate value (8) and the two-dimensional point Y coordinate value (9) of the corresponding two-dimensional point (7) can be obtained through the two-dimensional point X coordinate value reference (11) and the two-dimensional point Y coordinate value reference (12) of the three-dimensional point (10) in the three-dimensional point data chain (5); the three-dimensional point (10) corresponds to the unit vertex (1), and the three-dimensional point Z coordinate value (13) is the Z coordinate value of the unit vertex (1); The composition relationship of the VGTP group includes all information for generating all VGTP units in the VGTP group and their corresponding attribute information (3).

2. A data storage method for a generalized triangular prism model with vertical side edges according to claim 1, characterized in that: The root two-dimensional point data chain is stored in a quadtree root-branch-leaf data format according to the plane position of the two-dimensional point (7) contained therein; the quadtree root-branch-leaf data format is: A rectangular area whose edge includes all the two-dimensional points (7) in the root two-dimensional point data chain is determined on the plane, which is called the root rectangular area; the edge inclusion means that all the two-dimensional points (7) in the root two-dimensional point data chain are located in the root rectangular area or on the edge; Repeat the division of the root rectangular area and the rectangular area formed after the root rectangular area is divided in the form of rectangular quartering until the number of two-dimensional points (7) contained in the partial edges of all the leaf rectangular areas is no more than w, w≥1; the rectangular quartering refers to dividing the rectangular area into four rectangular areas of the same size; the leaf rectangular area refers to a rectangular area obtained by dividing the root rectangular area u times and not divided again, called a u-depth leaf rectangular area, u≥1; the rectangular area obtained by dividing the root rectangular area u times and divided again is called a u-depth branch rectangular area; The data format of the quadtree root-branch-leaf is stored as follows: the two-dimensional points (7) contained in some edges in the leaf rectangular area are stored in the leaf rectangular area; the u+1 depth leaf rectangular area or the u+1 depth branch rectangular area obtained by segmenting the u depth branch rectangular area is stored in the u depth branch rectangular area; the 1 depth leaf rectangular area or the 1 depth branch rectangular area obtained by segmenting the root rectangular area is stored in the root rectangular area; The two-dimensional point (7) contained in the partial edges of the u-depth leaf rectangular area refers to the two-dimensional point (7) located in the leaf rectangular area and on its partial edges; when the partial edges of the leaf rectangular area refer to the two-dimensional point (7) located on the common edge of the leaf rectangular area, the two-dimensional point (7) can only be contained in one of the leaf rectangular areas.

3. A data storage method for a generalized triangular prism model with vertical side edges according to claim 2, characterized in that: The composition relationship of the VGTP group is specifically: num-1 VGTP units and corresponding num-1 attribute information (3) are sequentially connected from num three-dimensional point groups (4) in the VGTP group composition relationship, forming a VGTP group; num≥2; The number of the three-dimensional point group (4) is represented by arr or arr plus or minus a positive integer. The three-dimensional point group (4) contains three three-dimensional point references (6), and the three-dimensional point references (6) have group numbers of 1, 2, and 3 respectively. The num three-dimensional point groups (4) are connected in sequence to form num-1 VGTP units, specifically: according to the numbering sequence of the three-dimensional point groups (4), the three-dimensional point references (6) in the three-dimensional point groups (4) numbered arr and arr+1 are respectively used to form two triangular bases and two / three side faces, and enclose a VGTP unit; forming two / three side faces means selecting two three-dimensional point references (6) in one three-dimensional point group (4) and connecting them with two three-dimensional point references (6) in another three-dimensional point group (4) in sequence. Two three-dimensional point references (6) with the same serial number are compared to form a quadrilateral side, a triangular side or no face, specifically: if the two selected three-dimensional point references (6) do not overlap with the two three-dimensional point references (6) with the same serial number in another three-dimensional point group (4), then a quadrilateral side is formed; if the two selected three-dimensional point references (6) and the two three-dimensional point references (6) with the same serial number in another three-dimensional point group (4) have a pair of three-dimensional point references (6) with the same serial number overlap, then a triangular side is formed; if the two selected three-dimensional point references (6) and the two three-dimensional point references (6) with the same serial number in another three-dimensional point group (4) have two pairs of three-dimensional point references (6) with the same serial number overlap, then no face is formed; The starting value of arr is the number of the first three-dimensional point group (4). Each time a VGTP unit is formed, arr increases by 1. The number of the num-1 attribute information (3) is represented by pro or a positive integer plus or minus pro, and the starting value of pro is the number of the first group of attribute information (3); the attribute information (3) corresponding to the VGTP unit in the VGTP group constitution relationship is specifically: each time the VGTP unit is constituted, the attribute information (3) numbered pro is obtained, and then pro is incremented by 1; The method of sequentially connecting the num three-dimensional point groups (4) to form num-1 VGTP units is called a VGTP intra-group unit formation method; The three-dimensional point reference (6) in the three-dimensional point group (4) of the VGTP group structure relationship corresponds to three different three-dimensional point data chains (5), and the three-dimensional point (10) in the three-dimensional point data chain (5) can be directly obtained through the three-dimensional point reference (6); The storage order of the three-dimensional point group (4) in the composition relationship of the VGTP group satisfies that the Z coordinate values ​​of the unit bottom surface (2) constructed in sequence according to the storage order of the three-dimensional point group (4) are distributed from large to small.

4. A data storage method for a generalized triangular prism model with vertical side edges according to claim 3, characterized in that: The sectioning process includes the following steps: Step 1: Get VGTP model data Obtain all the data of the VGTP model and store it according to the basic data structure of the data storage method; Step 2: Determine the VGTP group that needs to be dissected Selecting a spatial sectioning plane (18), and determining the VGTP group to be sectioned according to the plane position relationship between the spatial sectioning plane (18) and the rectangular area and the spatial relationship between the VGTP groups; Step 3, sectioning the VGTP group Obtain the set of VGTP groups to be sectioned and the spatial section plane (18) in step 2, and adjust the composition relationship of the root two-dimensional point data chain, the three-dimensional point data chain (5) and the VGTP group according to the intersection relationship between each VGTP group to be sectioned and the spatial section plane (18).

5. A data storage method for cutting a generalized triangular prism model with vertical side edges according to claim 4, characterized in that: The spatial sectioning surface (18) is a closed surface composed of a plurality of continuous spatial planes; the spatial planes satisfy the condition that each spatial plane is an arbitrary polygonal spatial plane with a finite area, and each edge of each spatial plane is a common edge of other spatial planes, and the spatial planes are called sectioning sub-surfaces; the closure means that the spatial sectioning surface (18) itself can enclose a complete closed space, and the part of the VGTP model located in the closed space is the part that needs to be excavated.

6. A data storage method for cutting a generalized triangular prism model with vertical side edges according to claim 5, characterized in that: Step 2 specifically includes the following steps: Step 2.1, projecting the multiple cutting sub-surfaces constituting the spatial cutting surface (18) onto the same horizontal plane along the vertical direction to obtain multiple horizontal projection planes, and at the same time obtaining the union of the multiple horizontal projection planes after projection according to Boolean operation, and finally obtaining a polygonal horizontal plane, which is called the cutting projection plane (17); the cutting projection plane (17) is a two-dimensional polygonal plane without a Z coordinate value; Step 2.2, searching according to the quadtree structure to screen out all leaf rectangular areas intersecting with the section projection plane (17), includes the following steps: Step 2.2.1, determine whether the cutting projection surface (17) intersects with the root rectangular area; if not, end the cutting process and keep all the data of the VGTP model unchanged; if intersecting, set u=1, and set the search range to the root rectangular area, and execute step 2.2.2; Step 2.2.2, determine the u-depth branch rectangular area or u-depth leaf rectangular area intersecting with the section projection plane (17) in the rectangular area stored corresponding to the search range; record the u-depth leaf rectangular area intersecting with the section projection plane (17) as the intersecting leaf rectangular area; reset the search range to the u-depth branch rectangular area intersecting with the section projection plane (17); set u=u+1, and repeat step 2.2.2 until no branch rectangular area in the rectangular area stored corresponding to the search range intersects with the section projection plane (17); The intersecting leaf rectangular areas recorded in step 2.2.2 are all the leaf rectangular areas finally screened and obtained in step 2.2 that intersect with the section projection surface (17); Step 2.3, obtaining all the two-dimensional points (7) stored in all the leaf rectangular regions intersecting with the section projection surface (17) in step 2.2, and recording them as possible intersecting two-dimensional points; Step 2.4, obtaining all three-dimensional point data chains (5) corresponding to the possible intersecting two-dimensional points, and obtaining the VGTP group generated by referencing the three-dimensional point (10) therein according to the three-dimensional point data chain (5), and storing it in the possible intersecting VGTP group set; Step 2.5, determine whether each VGTP group in the set of possible intersecting VGTP groups intersects with the spatial section plane (18) in space one by one, record all VGTP groups that intersect with the spatial section plane (18) as VGTP groups to be sectioned, and put them into the same set, which is called the set of VGTP groups to be sectioned.

7. A data storage method for cutting a generalized triangular prism model with vertical side edges according to claim 6, characterized in that: Step 3 specifically includes the following steps: Step 3.1, select a VGTP group from the set of VGTP groups to be sectioned as the VGTP group to be sectioned, read the composition relationship of the VGTP group to be sectioned and the three three-dimensional point data chains (5) where the three-dimensional point (10) referenced by it is located; read the spatial sectioning plane (18); Step 3.2, calculating the intersection surface between each sectioning sub-surface in the spatial sectioning surface (18) and each VGTP unit in the VGTP group; the intersection surface is the portion of the sectioning sub-surface located in the VGTP unit, which can be any polygonal spatial plane, called a sub-intersection surface; Step 3.3, obtaining the unit bottom surface (2) with the largest Z coordinate value in the VGTP group to be sectioned, projecting all sub-intersecting surfaces along the vertical direction onto the unit bottom surface (2), and obtaining projection traces and trace points; the projection traces are the edges in the projection surface of the sub-intersecting surfaces that do not completely or partially overlap with the edges of the projected unit bottom surface (2); the trace points include the endpoints of the traces and the intersection points of the traces; Step 3.4, adding a new trace line in the projected unit bottom surface (2), all trace lines including the new trace line can divide the projected unit bottom surface (2) into k triangular sub-surfaces; the endpoints of the new trace line are trace line points or vertices of the projected unit bottom surface (2); the new trace line does not intersect with the existing trace line; Step 3.5, generating two-dimensional points (7) equal in number to the number of trace points according to the coordinate values ​​of the trace points, specifically extracting the X coordinate value and Y coordinate value of each trace point as the X coordinate value and Y coordinate value of the newly generated two-dimensional point (7); all the two-dimensional points (7) newly generated from the trace points are referred to as the two-dimensional points to be added (14), and the number is recorded as g; According to the number of the two-dimensional points (14) to be added, g new three-dimensional point data chains (15) are generated, and stored in one-to-one correspondence with each of the two-dimensional points (14) to be added, and the corresponding storage relationship satisfies the corresponding storage relationship between the two-dimensional point (7) in the root two-dimensional point data chain of the data basic structure of the data storage method and the three-dimensional point data chain (5); the three-dimensional point Z coordinate value (13) of the first three-dimensional point (10) of the g new three-dimensional point data chains (15) is the Z coordinate value of the trace point of the two-dimensional point (14) to be added corresponding to the new three-dimensional point data chain (15), and the three-dimensional point Z coordinate values ​​(13) of the remaining three-dimensional points (10) of the g new three-dimensional point data chains (15) are to be determined by simulated projection; Add k new VGTP groups to constitute a relationship; the first three-dimensional point group (4) in the new k VGTP groups to constitute a relationship meets the requirements: the k triangular faces formed by the three three-dimensional point references (6) in the first three-dimensional point group (4) in each new VGTP group completely overlap with the k triangular sub-faces described in step 3.4 in a one-to-one correspondence; the three three-dimensional point references (6) in the first three-dimensional point group (4) in each new VGTP group are all referenced from g new three-dimensional point data chains (15) and the first three-dimensional point (10) in the three three-dimensional point data chains (5) read in step 3.1; the remaining three-dimensional point groups (4) and attribute information (3) of the new VGTP group to be simulated projection and volume inclusion relationship determination; Step 3.6, carrying out the simulated projection described in step 3.5, specifically includes the following steps: Step 3.6.1, obtain g newly added three-dimensional point data chains (15) and the first three-dimensional point (10) in the three three-dimensional point data chains (5) read in step 3.1, which is called the starting simulation projection point; successively project the starting simulation projection point to the simulated projection surface along the vertical direction; the simulated projection surface includes the unit bottom surface (2) in the VGTP group to be cut obtained in step 3.1, excluding the unit bottom surface (2) with the largest Z coordinate value, and the sub-intersecting surface described in step 3.2; In the process of successive projection, a three-dimensional point (10) is added to the three-dimensional point data chain (5) or the newly added three-dimensional point data chain (15) where the starting simulated projection point of the successful projection is located, and the three-dimensional point Z coordinate value (13) of the newly added point is the Z coordinate value obtained during the successful projection; the successful projection means that a unique solution can be obtained within or on the edge of the simulated projection surface during the projection process; In the sequential projection process, when a new three-dimensional point (10) is added to a three-dimensional point data chain (5) or a new three-dimensional point data chain (15), when there are three different three-dimensional point data chains (5) or three-dimensional point data chains (15) each having a new three-dimensional point (10) that satisfies the three-dimensional point group composition relationship, a new three-dimensional point group (4) is added to the corresponding new VGTP group composition relationship (16); The three-dimensional point group composition relationship satisfies that three different three-dimensional point data chains (5) or newly added three-dimensional point data chains (15) each add a three-dimensional point (10) in the same projection process, and the three corresponding starting simulated projection points are simultaneously referenced by the first three-dimensional point group (4) in the same newly added VGTP group composition relationship (16) in step 3.5; the newly added three-dimensional point group (4) in the corresponding newly added VGTP group composition relationship (16) refers to the three newly added three-dimensional points (10) that satisfy the composition relationship of the three-dimensional point group (4) according to the reference serial numbers of the three starting simulated projection points in the first three-dimensional point group (4) in the newly added VGTP group composition relationship (16); Step 3.6.2, obtaining the 3D point data chain (5) or the 3D point data chain (15) in which the newly added 3D point (10) is present in step 3.6.1, obtaining points with the same 3D point Z coordinate values ​​(13) through one-to-one comparison, merging them into one point, and pointing the reference relationship of the merged point to the merged point; The merging in step 3.6.2 needs to be performed according to the storage sequence number of the merged point in the three-dimensional point data link (5) or the newly added three-dimensional point data link (15), specifically: only the merged point with the smallest storage sequence number is retained as the merging point, and it is ensured that the storage address does not change when the merged point with the smallest storage sequence number is changed to the merging point; Step 3.6.3, obtaining the newly added VGTP group composition relationship (16) after executing step 3.6.2, adjusting the storage order of the three-dimensional point group (4) in each newly added VGTP group, so that the storage order of the three-dimensional point group (4) in each newly added VGTP group composition relationship (16) after adjustment satisfies that the Z coordinate value of the unit bottom surface (2) constructed in sequence according to the storage order of the three-dimensional point group (4) obeys the distribution from large to small; Step 3.7, determining the attribute information (3) in the newly added VGTP group composition relationship (16) according to the body inclusion relationship described in step 3.5, specifically: Obtain the three-dimensional point group (4) in the newly added VGTP group composition relationship (16) described in step 3.6.3, and construct VGTP units in sequence according to the unit composition method within the VGTP group. Each time a VGTP unit is constructed, determine the spatial inclusion relationship between the newly constructed VGTP unit and the VGTP units in the VGTP group to be cut described in step 3.1 and the spatial cutting surface (18), and determine the attribute information (3) in the newly added VGTP group composition relationship (16); The determining of the attribute information (3) through the spatial inclusion relationship is specifically as follows: if the newly constructed VGTP unit of the newly added VGTP group composition relationship (16) is completely located in a VGTP unit in the VGTP group to be sectioned and is not located in the spatial section plane (18), then a new attribute information (3) is added to the newly added VGTP group composition relationship (16), and the newly added attribute information (3) is the attribute information (3) of the VGTP unit in the VGTP group to be sectioned; if the newly constructed VGTP unit of the newly added VGTP group composition relationship (16) is completely located in the closed space of the spatial section plane (18), then a new attribute information (3) is added to the newly added VGTP group composition relationship (16), and the attribute information (3) is NULL; Step 3.8, merge the three-dimensional point group (4) corresponding to NULL in the attribute information (3) of the VGTP group composition relationship (16) to be added, and perform deletion judgment, specifically: Step 3.8.1, determine whether there is a NULL attribute information (3) with a continuous number in the newly added VGTP group composition relationship (16), and if so, read the starting number proDS and the ending number proDE of the continuous number; read the first three-dimensional point group (4) number arrS and the first attribute information (3) number proS in the newly added VGTP group composition relationship (16); Step 3.8.2, delete the attribute information numbered from proDS+1 to proDE (3), and delete the three-dimensional point group numbered from arrS+(proDS+1-proS) to arrS+(proDE-proS) (4); Step 3.8.3, after executing step 3.8.2 for all newly added VGTP group composition relationships (16), determine whether the attribute information (3) with the largest or smallest number is NULL, and perform the deletion operation based on the determination result, specifically: if the newly added VGTP group composition relationship (16) has only one set of attribute information (3) and it is NULL, then delete the newly added VGTP group composition relationship (16); if the attribute information (3) in the newly added VGTP group composition relationship (16) is greater than one set, and the attribute information (3) with the largest number is NULL, then delete the attribute information (3) with the largest number and the three-dimensional point group (4) in the newly added VGTP group composition relationship (16); if the attribute information (3) in the newly added VGTP group composition relationship (16) is greater than one set, and the attribute information (3) with the smallest number is NULL, then delete the attribute information (3) with the smallest number and the three-dimensional point group (4) in the newly added VGTP group composition relationship (16); Step 3.8.4, renumbering the three-dimensional point group (4) and attribute information (3) in the remaining newly added VGTP group composition relationship (16), requiring that the size relationship of the renumbered three-dimensional point group (4) and attribute information (3) remains unchanged and satisfies an arithmetic progression with a tolerance of 1; Step 3.8.5, search the g newly added three-dimensional point data chains (15), and remove the three-dimensional points (10) that are not referenced by the newly added VGTP group composition relationship (16) from the corresponding newly added three-dimensional point data chains (15). If all the three-dimensional points (10) in the newly added three-dimensional point data chain (15) are removed, delete the newly added three-dimensional point data chain (15), and delete the corresponding two-dimensional point to be added (14) at the same time; Step 3.8.6, adding the two-dimensional points to be added (14) generated during the execution of steps 3.1-3.8 to the set of two-dimensional points added during the sectioning; adding the new VGTP group composition relationship (16) generated during the execution of steps 3.1-3.8 to the set of new VGTP group composition relationship during the sectioning; Step 3.9, performing steps 3.1-3.8 on the remaining VGTP groups to be dissected in the set of VGTP groups to be dissected described in step 2; Step 3.10, obtaining the three-dimensional point data chain (5) where the three-dimensional points (10) referenced by all the VGTP groups to be sectioned in the set of VGTP groups to be sectioned described in step 2 are located, and removing the three-dimensional points (10) that are not referenced by the newly added VGTP group constituent relationship (16) in the set of newly added VGTP groups to be sectioned. If all the three-dimensional points (10) in the three-dimensional point data chain (5) are removed, then delete the three-dimensional point data chain (5), and at the same time delete the two-dimensional points (7) in the corresponding root two-dimensional point data chain; Step 3.11, all the newly added two-dimensional points in the set of newly added two-dimensional points are stored in the root two-dimensional point data chain, and at the same time, the two-dimensional points to be added (14) are stored in the corresponding leaf rectangular area according to the position of the two-dimensional points to be added (14); the original leaf rectangular area to which the two-dimensional points to be added (14) are to be added is further divided into four equal parts, until the final leaf rectangular area contains at most w two-dimensional points (7), w≥1, and the re-divided area is renamed according to the quadtree naming rule; Step 3.12, deleting the composition relationship of all VGTP groups to be dissected in the set of VGTP groups to be dissected described in step 2.

8. A data storage method for cutting a generalized triangular prism model with vertical side edges according to claim 1, characterized in that: The rectangular area is stored using a two-dimensional rectangular plane record without a Z coordinate value.

9. A data storage method for cutting a generalized triangular prism model with vertical side edges according to claim 2, characterized in that: The two-dimensional points (7) in the root two-dimensional point data chain will increase or decrease during the sectioning process; and the corresponding two-dimensional points (7) stored in the leaf rectangular area will change accordingly with the increase or decrease of the root two-dimensional point data chain.

10. A data storage method for cutting a generalized triangular prism model with vertical side edges according to claim 1, characterized in that: The Z coordinate value of the unit bottom surface (2) is the Z coordinate value of the centroid point of the unit bottom surface (2), that is, the geometric center point.

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