Three-dimensional solid model construction method and system

Abstract

This invention provides a method and system for constructing a three-dimensional solid model. The method includes: determining a topological structure diagram of a three-dimensional solid object based on its projection plane; simplifying the three-dimensional solid object; updating the topological structure diagram if topological conflicts exist during the simplification process; and determining a model of the three-dimensional solid object based on the simplified three-dimensional solid object and the updated topological structure diagram. The system is used to execute the above method. The three-dimensional solid model construction method and system provided by this invention, by constructing a topological structure diagram of a three-dimensional solid object, such as a three-dimensional building object, and handling the topological relationships between three-dimensional building objects, can reduce simplification steps while maintaining the consistency of the topological structure of the three-dimensional building objects.

Description

Technical Field

[0001] This invention relates to the field of computer technology, and in particular to a method and system for constructing three-dimensional solid models. Background Technology

[0002] Reasonable geometric simplification of 3D solid models, such as 3D building models, can reduce structural complexity and data size while maintaining visual consistency, thereby reducing graphics rendering pressure and improving scene interaction experience. The simplification of 3D building models should, on the one hand, gradually remove details to achieve simplification; on the other hand, it should maintain its right angles, area, position, and other characteristics to conform to the basic laws of spatial expression and cognition, while also ensuring the topological relationships between building objects.

[0003] Existing technologies often simplify 3D building models based on general simplification methods:

[0004] Simplification based on vertex clustering: First, the mesh is spatially clustered, and then the mesh is simplified by merging vertices in the same cluster. During the simplification process, each vertex in the cluster is replaced by the representative vertex with the highest weight in the cluster, and then the simplified model is formed by topological reconstruction of the representative vertices.

[0005] Simplification based on projection: This method first projects the 3D model onto a 2D plane to obtain the projected outline of the model. Then, it uses 2D drawing generalization technology to simplify and generalize the outline, and finally restores the 3D model from the simplified and generalized result.

[0006] Symbolic representation involves summarizing the characteristics of existing buildings to obtain a limited number of templates. Common modern urban building bases can be categorized into square, L-shaped, T-shaped, etc., and roofs into pyramid, gable, A-shaped, etc. After classification, the matching 3D symbols are selected by calculating the similarity between the actual model and the templates.

[0007] Applying general simplification methods directly to 3D building models may violate the model's inherent geometric constraints, severely damaging the building's appearance. Furthermore, simplification algorithms for building objects primarily focus on simplifying the entire building model, considering the roof, walls, and base planes simultaneously. While this can reduce redundancy to some extent, it easily disrupts the topological features between building objects. Summary of the Invention

[0008] The three-dimensional solid model construction method and system provided by the present invention are used to solve at least one of the above-mentioned problems in the prior art. By constructing a topological structure diagram of three-dimensional solid objects, such as three-dimensional building objects, and processing the topological relationships between three-dimensional building objects, the simplified steps of constructing three-dimensional building object models can be reduced while maintaining the consistency of the topological structure of three-dimensional building objects.

[0009] This invention provides a method for constructing a three-dimensional solid model, comprising:

[0010] Determine the topological structure diagram of the three-dimensional solid object based on its projection plane;

[0011] Simplify 3D solid objects;

[0012] In the event of a topological conflict during the simplification of the projection plane, the topological structure diagram is updated.

[0013] The model of the 3D solid object is determined based on the simplified 3D solid object and the updated topology diagram.

[0014] According to a method for constructing a three-dimensional solid model provided by the present invention, the step of determining the topological structure diagram of the three-dimensional solid object based on the projection plane of the three-dimensional solid object includes:

[0015] The three-dimensional solid objects are abstracted as points, and the common surfaces of adjacent three-dimensional solid objects are abstracted as edges;

[0016] The topological structure graph is determined based on the points and the edges;

[0017] The common surface is determined based on the boundary of the three-dimensional solid object;

[0018] The boundary is obtained after performing topological relationship processing on the projection surface.

[0019] According to a method for constructing a three-dimensional solid model provided by the present invention, the simplification of the three-dimensional solid object includes:

[0020] The elevation of the roof surface of the three-dimensional solid object is simplified based on the average height of all roof surfaces of the three-dimensional solid object.

[0021] The average height of all the roof surfaces is determined based on the volume of the three-dimensional solid object and the area of ​​its bottom surface.

[0022] According to a method for constructing a three-dimensional solid model provided by the present invention, the simplification of the three-dimensional solid object further includes:

[0023] The projection surface of the three-dimensional solid object is simplified in the following way:

[0024] All line segments constituting the projection surface are arranged in ascending order of length, and all line segments in ascending order are added to a preset set;

[0025] The shortest line segment in the updated preset set is taken as the current line segment, and it is determined whether the length of the current line segment is less than or equal to the length threshold. If so, the current line segment is simplified.

[0026] Determine whether the length of the adjacent line segment of the current line segment is less than or equal to the length threshold. If so, delete the common point of the current line segment and the adjacent line segment, and take the line segment formed by the endpoints of the current line segment and the adjacent line segment as the simplified line segment.

[0027] The updated preset set is determined by adding the simplified line segments to the preset set.

[0028] According to a method for constructing a three-dimensional solid model provided by the present invention, the simplification of the projection surface of the three-dimensional solid object further includes:

[0029] If the length of the adjacent line segments of the current line segment in the updated preset set is greater than the length threshold, then a target simplification operation is used to simplify the current line segment, the line segment preceding the current line segment, and the line segment following the current line segment to obtain a simplified line segment.

[0030] According to a three-dimensional solid model construction method provided by the present invention, the step of simplifying the current line segment, the previous line segment, and the next line segment of the current line segment using a target simplification operation to obtain a simplified line segment includes:

[0031] If the first included angle is less than or equal to the angle threshold, then the current line segment is translated, and the line segment formed by merging the previous line segment, the current line segment, and the next line segment is taken as the simplified line segment;

[0032] If the second included angle is less than or equal to the angle threshold, then the line segment formed by connecting the non-common vertices of the previous line segment, the current line segment, and the next line segment is taken as the simplified line segment.

[0033] If both the first included angle and the second included angle are greater than the angle threshold, then when the shortest distance from the two endpoints of the current line segment to the target intersection point is less than or equal to the distance threshold, the intersection extension of the previous line segment and the next line segment is taken as the simplified line segment.

[0034] The first included angle is determined by taking the current line segment as the starting side, counterclockwise as the positive direction, and based on the difference between the minimum angle formed by the previous line segment and the current line segment and the minimum angle formed by the next line segment and the current line segment.

[0035] The second included angle is determined by taking the current line segment as the starting side, counterclockwise as the positive direction, and based on the sum of the minimum angle formed by the previous line segment and the current line segment and the minimum angle formed by the next line segment and the current line segment;

[0036] The target intersection point is determined based on the intersection point of the extensions of the preceding line segment and the following line segment.

[0037] According to a three-dimensional solid model construction method provided by the present invention, updating the topology diagram when topological conflicts exist during the simplification of the projection plane includes:

[0038] If a topological conflict exists during the simplification process of the projection surface, the surface where the topological conflict occurs will be treated as a newly added edge.

[0039] The newly added edge is added to the topology graph to update the topology graph;

[0040] The topological conflict refers to the overlap of the boundaries of the simplified projection planes.

[0041] The present invention also provides a three-dimensional solid model construction system, comprising:

[0042] The module includes a structure determination module, a simplification module, a structure update module, and a model building module.

[0043] The structure determination module is used to determine the topological structure diagram of the three-dimensional solid object based on the projection surface of the three-dimensional solid object;

[0044] The simplification module is used to simplify the three-dimensional solid object;

[0045] The structure update module is used to update the topology diagram when there is a topology conflict in the simplification process of the first target surface.

[0046] The model building module is used to determine the model of the three-dimensional entity object based on the simplified three-dimensional entity object and the updated topology diagram.

[0047] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of any of the three-dimensional solid model construction methods described above.

[0048] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the three-dimensional solid model construction methods described above.

[0049] The three-dimensional solid model construction method and system provided by the present invention can reduce the number of simplified steps in constructing three-dimensional building object models while maintaining the consistency of the topological structure of the three-dimensional building objects by constructing a topological structure diagram of three-dimensional solid objects such as three-dimensional building objects and processing the topological relationships between three-dimensional building objects. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0051] Figure 1 This is a flowchart illustrating the three-dimensional solid model construction method provided by the present invention;

[0052] Figure 2 This is a schematic diagram of the process for constructing a three-dimensional building model provided by the present invention;

[0053] Figure 3 This is a flowchart illustrating the simplification process of the projection surface provided by the present invention;

[0054] Figure 4 This is a schematic diagram of the structure of the three-dimensional solid model construction system provided by the present invention;

[0055] Figure 5 This is a schematic diagram of the physical structure of the electronic device provided by the present invention. Detailed Implementation

[0056] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0057] Figure 1 This is a flowchart illustrating the three-dimensional solid model construction method provided by the present invention, as shown below. Figure 1 As shown, the method includes:

[0058] S1. Determine the topological structure diagram of the three-dimensional solid object based on its projection plane;

[0059] S2. Simplify the three-dimensional solid object;

[0060] S3. If there are topological conflicts during the simplification of the projection plane, update the topology diagram.

[0061] S4. Based on the simplified 3D solid object and the updated topology diagram, determine the model of the 3D solid object.

[0062] It should be noted that the above method can be implemented by computer equipment.

[0063] Optionally, based on the projection surface of the three-dimensional solid object, a topological structure diagram of the three-dimensional solid object to be constructed is obtained, and the elevation of the three-dimensional solid object is simplified to obtain the simplified elevation.

[0064] Next, the projection surface is simplified to obtain the simplified projection surface.

[0065] During the simplification of the projection surfaces of a 3D solid object, it is necessary to determine whether there are topological conflicts. For example, if the projection surfaces overlap, a topological conflict is considered to exist during the simplification process. In this case, the topological structure diagram of the obtained 3D solid object needs to be updated. Based on the obtained projection surfaces, the simplified elevations, and the updated topological structure diagram of the 3D solid object, a model of the 3D solid object is constructed.

[0066] For example, when the 3D solid object is a 3D building object, by means of... Figure 2 The flowchart shown illustrates the model construction of a 3D building object, specifically:

[0067] First, construct the topological structure diagram of the 3D solid object based on the projection plane of the 3D building object;

[0068] Secondly, the elevation of the three-dimensional solid object is simplified to obtain the simplified elevation.

[0069] Next, the projection surface of the 3D building object is simplified to obtain the simplified projection surface. Then, it is determined whether there is a topological conflict during the simplification process. If there is, the topological structure diagram of the 3D building object is updated.

[0070] Finally, based on the simplified elevation, simplified projection plane, and updated topology diagram of the 3D building object obtained above, a model of the 3D building object is constructed, namely, the simplified model of the 3D building object.

[0071] The three-dimensional solid model construction method provided by the present invention, by constructing a topological structure diagram of three-dimensional solid objects such as three-dimensional building objects and processing the topological relationships between three-dimensional building objects, can reduce the number of simplified steps in constructing three-dimensional building object models while maintaining the consistency of the topological structure of three-dimensional building objects.

[0072] Furthermore, in one embodiment, step S1 may specifically include:

[0073] S11. Abstract three-dimensional solid objects as points, and abstract the common faces of adjacent three-dimensional solid objects as edges;

[0074] S12. Determine the topological structure diagram based on the points and edges;

[0075] The common surface is determined based on the boundary of the three-dimensional solid object;

[0076] The boundary is obtained after processing the topological relationships of the projection surface.

[0077] Optionally, the boundary of the three-dimensional entity object is obtained by performing topological relationship processing on the projection surface of the three-dimensional entity object based on the target information processing software. Then, the three-dimensional entity object is abstracted into "points", and the common surface of adjacent three-dimensional entity objects is abstracted into "edges". The topological structure diagram of the three-dimensional entity object is constructed based on the "points" and "edges".

[0078] It should be noted that the overlapping surfaces of adjacent 3D solid objects are called common surfaces.

[0079] For example, when constructing a topological map of a 3D building object, the boundaries of the 3D building object are first obtained through geographic information processing software; then, the 3D building object is abstracted into "points", and the common surface of adjacent 3D building objects is abstracted into "edges" to construct the topological map of the 3D building object.

[0080] The three-dimensional solid model construction method provided by this invention is based on the topological structure diagram of the constructed three-dimensional solid object, such as a three-dimensional building object. This facilitates timely processing of the topological structure diagram of the three-dimensional building object, thereby avoiding the destruction of geometric constraints in the model of the three-dimensional building object during the simplification process, which would result in the final model of the three-dimensional building object being inconsistent with the actual three-dimensional building object.

[0081] Furthermore, in one embodiment, step S2 may specifically include:

[0082] S21. Simplify the elevation of the roof surface of the 3D solid object based on the average height of all roof surfaces of the 3D solid object;

[0083] The average height of all roof surfaces is determined based on the volume of the 3D solid object and the area of ​​its bottom surface.

[0084] Optionally, based on the topology diagram of the 3D solid object, all roof surfaces corresponding to the 3D solid object can be found and added to a collection List. <surfaces>In the above list, the elevation of a three-dimensional solid object can be determined based on the aforementioned set List. <surfaces>The average height of all faces in the set is obtained, specifically, from the collection List. <surfaces>The average height of all faces is obtained by taking the ratio of the volume of the three-dimensional solid object composed of all faces to the area of ​​the bottom face of the three-dimensional solid object. This average height is then used as the simplified elevation to simplify the elevation of all roof faces of the three-dimensional solid object.

[0085] For example, when simplifying the elevation of the roof surface of a 3D building object, the top surface boundary is simplified. Since the roof surface of the 3D building object may be a discontinuous surface, the bottom surface of the 3D building object is used as the boundary of the simplified roof surface.

[0086] Find all roof faces based on the topology diagram of the 3D building object and add them to the collection List. <surfaces>middle.

[0087] The elevation of the roof surface is simplified; the elevation is obtained from a list. <surfaces>The average height of all faces in the set is obtained as shown in the following formula.

[0088]

[0089] Where k is a List <surfaces>The number of faces in the set and the average height are calculated by the ratio of the sum of the volumes of the three-dimensional solid objects composed of i planes to the area of ​​the building's base, so as to better reflect the actual height of the building.

[0090] The three-dimensional solid model construction method provided by the present invention simplifies the elevation of a three-dimensional solid object to obtain a simplified elevation (for example, simplifying the roof surface of a three-dimensional building object to obtain the elevation of the roof surface), which lays the foundation for subsequent construction of a model of a three-dimensional solid object such as a three-dimensional building object based on the above elevation.

[0091] Furthermore, in one embodiment, step S2 may further include:

[0092] S22. The projection surface of the three-dimensional solid object is simplified in the following way:

[0093] S221. Arrange all line segments constituting the projection plane in ascending order of length, and add all line segments after ascending order to a preset set;

[0094] S222. Take the shortest line segment in the updated preset set as the current line segment, and determine whether the length of the current line segment is less than or equal to the length threshold. If so, perform a simplification operation on the current line segment.

[0095] S223. Determine whether the length of the adjacent line segment is less than or equal to the length threshold. If so, delete the common point between the current line segment and the adjacent line segment, and take the line segment formed by the endpoints of the current line segment and the adjacent line segment as the simplified line segment.

[0096] The updated preset set is determined by adding the simplified line segments to the preset set.

[0097] Optionally, the simplification of the projection surface in the projection plane of a 3D building object is used as an example for illustration. The projection surface of the 3D building object is simplified, specifically as follows: Figure 3 As shown:

[0098] For polygon features, the shorter the line segments that make up the polygon feature, the smaller its impact on the overall shape of the space. Therefore, this can be addressed by creating a collection List. <segments>This sorts all the line segments that make up the bottom surface of the three-dimensional building object in ascending order of length.

[0099] List <segments>The shortest line segment is taken as the current line segment c and calculated. It is determined whether the length of the current line segment c is less than or equal to the length threshold t. If its length is less than or equal to the length threshold t, the current line segment is simplified. Otherwise, it is considered to be able to reflect the overall shape of the space and should be retained, and the simplification is terminated.

[0100] The simplification operation for the current line segment c can be as follows: determine whether the length of the adjacent line segment l is not less than or equal to the length threshold t. If the length of the adjacent line segment l is also less than or equal to the threshold t, then delete the common points of the two line segments, take the line segment formed by the endpoints of the two line segments as the simplified line segment, and add it to the set List. <segments>Iterative calculations are performed.

[0101] The three-dimensional solid model construction method provided by the present invention can retain the key structure of the three-dimensional building object and effectively reduce redundant data of the three-dimensional building object by simplifying the projection surface of the three-dimensional solid object (such as the projection surface of the three-dimensional building object).

[0102] Furthermore, in one embodiment, step S22 may further include:

[0103] S224. If the length of the adjacent line segments of the current line segment in the updated preset set is greater than the length threshold, then the target simplification operation is used to simplify the current line segment, the line segment before the current line segment, and the line segment after the current line segment to obtain the simplified line segment.

[0104] Optionally, when simplifying the projection plane of a 3D solid object, such as a 3D building object, the convex or concave features in the 3D building object should be extracted as detailed structures. Specifically:

[0105] If the length of the adjacent segment l of the current line segment c in the updated preset set is greater than the length threshold t, then the target simplification operation is used to combine the current line segment c and the preceding line segment l. p and the next line segment l of the current line segment n The shape composition is extracted into detailed structure(l) p ,c,l n Simplify the data to obtain the simplified line segments.

[0106] The three-dimensional solid model construction method provided by this invention simplifies the projection surface of three-dimensional solid objects (such as the projection surface of three-dimensional building objects). While retaining the key structure of the three-dimensional building objects, it also makes the detailed structure more in line with the construction rules of three-dimensional building objects through unified processing, and effectively reduces the redundant data of three-dimensional building objects.

[0107] Furthermore, in one embodiment, step S34 may specifically include:

[0108] S341. If the first included angle is less than or equal to the angle threshold, then translate the current line segment and merge the previous line segment, the current line segment, and the next line segment into the simplified line segment.

[0109] S342. If the second included angle is less than or equal to the angle threshold, then the line segment connecting the non-common vertices of the previous line segment, the current line segment, and the next line segment is taken as the simplified line segment.

[0110] S343. If both the first included angle and the second included angle are greater than the angle threshold, then when the shortest distance from the two endpoints of the current line segment to the target intersection point is less than or equal to the distance threshold, the intersection extension of the previous line segment and the next line segment is taken as the simplified line segment.

[0111] The first included angle is determined by taking the current line segment as the starting side, counterclockwise as the positive direction, and based on the difference between the minimum angle formed by the previous line segment and the current line segment and the minimum angle formed by the next line segment and the current line segment.

[0112] The second included angle is determined by taking the current line segment as the starting side, counterclockwise as the positive direction, and based on the sum of the minimum angle formed by the previous line segment and the current line segment and the minimum angle formed by the next line segment and the current line segment.

[0113] The target intersection point is determined based on the intersection point of the extensions of the preceding and following line segments.

[0114] Optionally, such as Figure 3 As shown, if the length of the adjacent line segment l of the current line segment c in the updated preset set is greater than the length threshold t, then the current line segment c and the preceding line segment l of the current line segment will be... p and the next line segment l of the current line segment n The shape composition is extracted into detailed structure(l) p ,c,l n Simplify the data to obtain the simplified line segments.

[0115] If the first included angle α is less than or equal to the angle threshold δ, it is considered a convex / concave structure, and the convex / concave structure is eliminated by translating the current line segment c.

[0116] If the second included angle β is less than or equal to the angle threshold δ, then the first line segment l will be... p The current line segment c and the next line segment l n Connect the non-common vertices into a line segment, and treat it as a simplified line segment.

[0117] If both the first included angle α and the second included angle β are greater than the angle threshold δ, then determine whether it is possible to extend the previous line segment l. p and the following line segment l n Connect the two line segments until they intersect. d represents the distance from the two endpoints of the current line segment c to the target intersection point o (the previous line segment l). p and the following line segment l n The shortest distance (the intersection of the two points) is given by r, where r is the distance threshold. When d ≤ r, the previous line segment l is used. p and the following line segment l n The intersecting extensions are simplified line segments, and these are added to the collection List. <segments>Iterative calculations are performed.

[0118] Finally, the simplified 3D building projection surface is output, and stretched to the elevation of the 3D building to generate a simplified 3D building object model.

[0119] The three-dimensional solid model construction method provided by this invention simplifies the projection of three-dimensional solid objects. While retaining the key structure of three-dimensional building objects, it uses target simplification operations to uniformly process the detailed structure, which is more in line with the construction rules of three-dimensional building objects and effectively reduces redundant data of three-dimensional building objects.

[0120] Furthermore, in one embodiment, step S4 may specifically include:

[0121] S41. If a topological conflict occurs during the simplification of the projection surface, the surface with the topological conflict will be added as a new edge.

[0122] S42. Add the newly added edges to the topology graph to update the topology graph.

[0123] Topological conflict occurs when the boundaries of the simplified projection surfaces overlap.

[0124] Optionally, a topological validity check is performed on the projection surface according to the topological structure diagram, and topological repair is performed. When simplifying the projection surface of the three-dimensional solid object, if there is a topological conflict during the simplification process, the surface with the topological conflict is added as a new edge and added to the topological structure diagram to update the topological structure diagram of the three-dimensional solid object.

[0125] For example, when simplifying the projection surfaces of a 3D building object, if a topological conflict occurs during the simplification process, i.e., the boundaries of the projection surfaces of the 3D building object overlap, the conflicting surfaces are treated as newly added "edges" and added to the topology graph to update the topology graph. If no topological conflict occurs, the simplification process continues. For topologically adjacent common surfaces, the same simplification method is used to maintain topological consistency.

[0126] The three-dimensional solid model construction method provided by this invention is based on the topological structure diagram of the constructed three-dimensional solid object, such as a three-dimensional building object, and updates the topological structure diagram of the three-dimensional building object when a topological conflict occurs, thereby ensuring the consistency of the topological structure of the three-dimensional building object.

[0127] The three-dimensional solid model construction system provided by the present invention is described below. The three-dimensional solid model construction system described below can be referred to in correspondence with the three-dimensional solid model construction method described above.

[0128] Figure 4 This is a schematic diagram of the structure of the three-dimensional solid model construction system provided by the present invention, as shown below. Figure 4 As shown, it includes: a structure determination module 410, a simplification module 411, a structure update module 412, and a model building module 413;

[0129] The structure determination module 410 is used to determine the topological structure diagram of the three-dimensional solid object based on the projection surface of the three-dimensional solid object.

[0130] Simplification module 411 simplifies 3D solid objects;

[0131] The structure update module 412 updates the topology diagram when there is a topological conflict during the simplification process of the projection plane.

[0132] The model building module 413 is used to determine the model of the three-dimensional solid object based on the simplified projection plane, the simplified elevation, and the updated topology diagram.

[0133] The three-dimensional solid model construction system provided by this invention constructs a topological structure diagram of three-dimensional solid objects, such as three-dimensional building objects, and processes the topological relationships between three-dimensional building objects. This reduces the number of simplified steps in constructing three-dimensional building object models while maintaining the consistency of the topological structure of the three-dimensional building objects.

[0134] Furthermore, in one embodiment, the structure determination module 410 is also used for:

[0135] Abstract 3D solid objects as points, and abstract the common surfaces of adjacent 3D solid objects as edges;

[0136] Determine the topological structure graph based on the points and edges;

[0137] The common surface is determined based on the boundary of the three-dimensional solid object;

[0138] The boundary is obtained after processing the topological relationships of the projection surface.

[0139] The three-dimensional solid model construction system provided by this invention is based on the topological structure diagram of the constructed three-dimensional solid object, such as a three-dimensional building object. This facilitates timely processing of the topological structure diagram of the three-dimensional building object, thereby avoiding the destruction of geometric constraints in the model of the three-dimensional building object during the simplification process, which would result in the final model of the three-dimensional building object being inconsistent with the actual three-dimensional building object.

[0140] Furthermore, in one embodiment, the simplification module 411 can also be specifically used for:

[0141] The elevation of the roof surface of the 3D solid object is simplified based on the average height of all roof surfaces of the 3D solid object.

[0142] The average height of all roof surfaces is determined based on the volume of the 3D solid object and the area of ​​its bottom surface.

[0143] The three-dimensional solid model construction system provided by this invention simplifies the elevation of three-dimensional solid objects to obtain simplified elevations (for example, simplifying the roof surface of a three-dimensional building object to obtain the elevation of the roof surface), laying the foundation for subsequent construction of three-dimensional solid objects such as three-dimensional building objects based on the above elevations.

[0144] Furthermore, in one embodiment, the simplification module 411 can also be used for:

[0145] The projection surface of the three-dimensional solid object is simplified in the following way:

[0146] Arrange all line segments that make up the projection plane in ascending order of length, and add all line segments in ascending order to a preset set;

[0147] The shortest line segment in the updated preset set is taken as the current line segment, and it is determined whether the length of the current line segment is less than or equal to the length threshold. If so, the current line segment is simplified.

[0148] Determine whether the length of the adjacent line segment is less than or equal to the length threshold. If so, delete the common point between the current line segment and the adjacent line segment, and take the line segment formed by the endpoints of the current line segment and the adjacent line segment as the simplified line segment.

[0149] The updated preset set is determined by adding the simplified line segments to the preset set.

[0150] The three-dimensional solid model construction system provided by this invention can retain the key structure of the three-dimensional building object and effectively reduce redundant data of the three-dimensional building object by simplifying the projection surface of the three-dimensional solid object (such as the projection surface of the three-dimensional building object).

[0151] Furthermore, in one embodiment, the simplification module 411 can also be used for:

[0152] If the length of the adjacent line segments of the current line segment in the updated preset set is greater than the length threshold, then the target simplification operation is used to simplify the current line segment, the line segment before the current line segment, and the line segment after the current line segment to obtain the simplified line segment.

[0153] The three-dimensional solid model construction system provided by this invention simplifies the projection surface of three-dimensional solid objects (such as the projection surface of three-dimensional building objects). While retaining the key structure of the three-dimensional building objects, it also makes the detailed structure more in line with the construction rules of three-dimensional building objects through unified processing, and effectively reduces redundant data of three-dimensional building objects.

[0154] Furthermore, in one embodiment, the simplification module 411 can also be used for:

[0155] If the first included angle is less than or equal to the angle threshold, then translate the current line segment and merge the previous line segment, the current line segment, and the next line segment into the simplified line segment.

[0156] If the second included angle is less than or equal to the angle threshold, then the line segment formed by connecting the non-common vertices of the previous line segment, the current line segment, and the next line segment is taken as the simplified line segment.

[0157] If neither of the above two conditions is met, then when the shortest distance from the two endpoints of the current line segment to the target intersection point is less than or equal to the distance threshold, the intersection extension of the previous line segment and the next line segment is taken as the simplified line segment.

[0158] The first included angle is determined by taking the current line segment as the starting side, counterclockwise as the positive direction, and based on the difference between the minimum angle formed by the previous line segment and the current line segment and the minimum angle formed by the next line segment and the current line segment.

[0159] The second included angle is determined by taking the current line segment as the starting side, counterclockwise as the positive direction, and based on the sum of the minimum angle formed by the previous line segment and the current line segment and the minimum angle formed by the next line segment and the current line segment.

[0160] The target intersection point is determined based on the intersection point of the extensions of the preceding and following line segments.

[0161] The three-dimensional solid model construction system provided by this invention simplifies the projection surface of three-dimensional solid objects (such as the projection surface of three-dimensional building objects). While retaining the key structure of the three-dimensional building objects, it uses target simplification operations to uniformly process the detailed structure, which is more in line with the construction rules of three-dimensional building objects and effectively reduces redundant data of three-dimensional building objects.

[0162] Furthermore, in one embodiment, the structure update module 412 can also be used for:

[0163] In the process of simplifying the projection plane, if there is a topological conflict, the face with the topological conflict will be added as a new edge.

[0164] Add the new edges to the topology graph to update the topology graph;

[0165] Topological conflict occurs when the boundaries of the simplified projection surfaces overlap.

[0166] The three-dimensional solid model construction system provided by this invention is based on the topological structure diagram of the constructed three-dimensional solid object, such as a three-dimensional building object, and updates the topological structure diagram of the three-dimensional building object when a topological conflict occurs, thereby ensuring the consistency of the topological structure of the three-dimensional building object.

[0167] Figure 5 This is a schematic diagram of the physical structure of an electronic device provided by the present invention, such as... Figure 5 As shown, the electronic device may include a processor 510, a communication interface 511, a memory 512, and a bus 513, wherein the processor 510, the communication interface 511, and the memory 512 communicate with each other via the bus 513. The processor 510 can call logical instructions in the memory 512 to execute the following methods:

[0168] Determine the topological structure diagram of the 3D solid object based on its projection plane;

[0169] Simplify 3D solid objects;

[0170] If topological conflicts exist during the simplification process of the projection plane, the topology diagram is updated.

[0171] The model of the 3D solid object is determined based on the simplified 3D solid object and the updated topology diagram.

[0172] Furthermore, the logical instructions in the aforementioned memory can be implemented as software functional units and sold or used as independent products, and can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer power supply (which may be a personal computer, server, or network power supply, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0173] Furthermore, this invention discloses a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium. The computer program includes program instructions, and when these instructions are executed by a computer, the computer can execute the three-dimensional solid model construction method provided in the above-described method embodiments, for example including:

[0174] Determine the topological structure diagram of the 3D solid object based on its projection plane;

[0175] Simplify 3D solid objects;

[0176] If topological conflicts exist during the simplification process of the projection plane, the topology diagram is updated.

[0177] The model of the 3D solid object is determined based on the simplified 3D solid object and the updated topology diagram.

[0178] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the three-dimensional solid model construction method provided in the above embodiments, including, for example:

[0179] Determine the topological structure diagram of the 3D solid object based on its projection plane;

[0180] Simplify 3D solid objects;

[0181] If topological conflicts exist during the simplification process of the projection plane, the topology diagram is updated.

[0182] The model of the 3D solid object is determined based on the simplified 3D solid object and the updated topology diagram.

[0183] The system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0184] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., including several instructions to cause a computer power supply (which may be a personal computer, server, or network power supply, etc.) to execute the methods described in various embodiments or some parts of the embodiments.

[0185] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.< / segments> < / segments> < / segments> < / segments> < / surfaces> < / surfaces> < / surfaces> < / surfaces> < / surfaces> < / surfaces>

Claims

1. A method for constructing a three-dimensional solid model, characterized in that, include: Determine the topological structure diagram of the three-dimensional solid object based on its projection plane; The three-dimensional solid object is simplified; If a topological conflict exists during the simplification process of the projection plane, the topological diagram is updated. The model of the three-dimensional entity object is determined based on the simplified three-dimensional entity object and the updated topology diagram; In the event of a topological conflict during the simplification process of the projection plane, updating the topology diagram includes: In the case of topological conflict during the simplification of the projection surface, the surface where the topological conflict occurs will be added as a new edge; The newly added edge is added to the topology graph to update the topology graph; The topological conflict refers to the overlap of the boundaries of the simplified projection planes; The three-dimensional solid objects include three-dimensional building objects.

2. The method for constructing a three-dimensional solid model according to claim 1, characterized in that, Determining the topological structure diagram of the three-dimensional solid object based on its projection plane includes: The three-dimensional solid objects are abstracted as points, and the common surfaces of adjacent three-dimensional solid objects are abstracted as edges; The topological structure graph is determined based on the points and the edges; The common surface is determined based on the boundary of the three-dimensional solid object; The boundary is obtained after performing topological relationship processing on the projection surface.

3. The method for constructing a three-dimensional solid model according to claim 1, characterized in that, The simplification of the three-dimensional solid object includes: The elevation of the roof surface of the three-dimensional solid object is simplified based on the average height of all roof surfaces of the three-dimensional solid object. The average height of all the roof surfaces is determined based on the volume of the three-dimensional solid object and the area of ​​its bottom surface.

4. The method for constructing a three-dimensional solid model according to claim 1, characterized in that, The simplification of the three-dimensional solid object also includes: The projection surface of the three-dimensional solid object is simplified in the following way: All line segments constituting the projection surface are arranged in ascending order of length, and all line segments in ascending order are added to a preset set; The shortest line segment in the updated preset set is taken as the current line segment, and it is determined whether the length of the current line segment is less than or equal to the length threshold. If so, the current line segment is simplified. Determine whether the length of the adjacent line segment of the current line segment is less than or equal to the length threshold. If so, delete the common point of the current line segment and the adjacent line segment, and take the line segment formed by the endpoints of the current line segment and the adjacent line segment as the simplified line segment. The updated preset set is determined by adding the simplified line segments to the preset set.

5. The method for constructing a three-dimensional solid model according to claim 4, characterized in that, The simplification of the projection surface of the three-dimensional solid object also includes: If the length of the adjacent line segments of the current line segment in the updated preset set is greater than the length threshold, then a target simplification operation is used to simplify the current line segment, the line segment preceding the current line segment, and the line segment following the current line segment to obtain a simplified line segment.

6. The method for constructing a three-dimensional solid model according to claim 5, characterized in that, The step of simplifying the current line segment, the preceding line segment, and the following line segment using a target simplification operation to obtain a simplified line segment includes: If the first included angle is less than or equal to the angle threshold, then the current line segment is translated, and the line segment formed by merging the previous line segment, the current line segment, and the next line segment is taken as the simplified line segment; If the second included angle is less than or equal to the angle threshold, then the line segment formed by connecting the non-common vertices of the previous line segment, the current line segment, and the next line segment is taken as the simplified line segment. If both the first included angle and the second included angle are greater than the angle threshold, then when the shortest distance from the two endpoints of the current line segment to the target intersection point is less than or equal to the distance threshold, the intersection extension of the previous line segment and the next line segment is taken as the simplified line segment. The first included angle is determined by taking the current line segment as the starting side, counterclockwise as the positive direction, and based on the difference between the minimum angle formed by the previous line segment and the current line segment and the minimum angle formed by the next line segment and the current line segment. The second included angle is determined by taking the current line segment as the starting side, counterclockwise as the positive direction, and based on the sum of the minimum angle formed by the previous line segment and the current line segment and the minimum angle formed by the next line segment and the current line segment; The target intersection point is determined based on the intersection point of the extensions of the preceding line segment and the following line segment.

7. A three-dimensional solid model construction system, characterized in that, include: The module includes a structure determination module, a simplification module, a structure update module, and a model building module. The structure determination module is used to determine the topological structure diagram of the three-dimensional solid object based on the projection surface of the three-dimensional solid object; The simplification module is used to simplify the three-dimensional solid object; The structure update module is used to update the topology diagram when there is a topology conflict in the simplification process of the projection surface. The model building module is used to determine the model of the three-dimensional entity object based on the simplified three-dimensional entity object and the updated topology diagram; The structure update module is specifically used to add the surface where the topological conflict occurs as a new edge when the topological conflict exists during the simplification process of the projection surface. The newly added edge is added to the topology graph to update the topology graph; The topological conflict refers to the overlap of the boundaries of the simplified projection planes; The three-dimensional solid objects include three-dimensional building objects.

8. An electronic device comprising a processor and a memory storing a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the three-dimensional solid model construction method according to any one of claims 1 to 6.

9. A processor-readable storage medium, characterized in that, The processor-readable storage medium stores a computer program that causes the processor to perform the steps of the three-dimensional solid model construction method according to any one of claims 1 to 6.

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