Building facade drawing method and system based on SouthMap and storage medium
By utilizing SouthMap software's 3D data processing and viewport collaboration technology, efficient and accurate calculation of building exterior wall area was achieved, solving the problems of low efficiency and error susceptibility in existing technologies and improving drawing efficiency and accuracy.
Patent Information
- Application Number
- CN202511217289.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-28
- Publication Date
- 2026-01-20
AI Technical Summary
The existing technology for calculating the area of building exterior walls is cumbersome, inefficient, and prone to errors, with a high degree of reliance on manual labor, making it difficult to meet the needs of efficient and accurate calculation for complex buildings.
The method of building facade drawing based on SouthMap is adopted. It uses automatic 3D data processing and collaborative generation with 2D and 3D viewports to generate building components through intelligent generation of building outlines and coordinate mapping. It uses 3D clipping plane equations to clip irregular wall surfaces and automatically calculates the area based on the orientation marker xh.
It improves drawing efficiency and accuracy, reduces reliance on manual labor, minimizes errors, and enhances the automation level of building exterior wall area calculation.
Smart Images
Figure CN121365442A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application relates to the technical field of architectural drawing, and particularly relates to a building facade drawing method and system based on SouthMap and a storage medium. BACKGROUND
[0002] In the design, construction, maintenance and reconstruction of a building, accurate calculation of the area of the outer wall of the building is a basic and crucial work. The outer wall area data is an important basis for reasonably estimating the amount of building materials (such as paint, insulation layer, curtain wall panel), scientifically preparing a maintenance or renovation budget, evaluating building energy consumption, and preparing an engineering quantity list. Whether the area of the outer wall can be accurately calculated directly affects the reliability of project cost control, the rationality of resource allocation and the efficiency of engineering implementation. However, the actual outer wall shape of a building is usually complex and variable, and is influenced by various factors, for example, concave-convex changes, curved surface modeling, non-standard geometric shapes (such as special-shaped corners, inclined wall surfaces), and a large number of components such as door and window openings, balconies, decorative lines, air conditioner positions and pipe wells existing on the outer wall surface, which need to be accurately identified and deducted from the total area.
[0003] In the prior art, it mainly relies on manual operation combined with general computer-aided design (CAD) software and point cloud processing software. The steps include: point cloud import and conversion: the operator first converts the three-dimensional laser scanning point cloud data collected on site into a format that can be recognized and loaded by CAD software using Autodesk ReCap or the like. Point cloud cropping and positioning: after loading the point cloud in the CAD environment, the operator needs to manually crop the part of the point cloud irrelevant to the target outer wall. Then, the coordinate system needs to be manually reoriented to accurately align the point cloud data to the actual coordinate or drawing coordinate system of the building, so as to accurately draw the plane. Manual drawing and labeling: the operator needs to face each outer wall one by one, manually track the point cloud contour using the drawing command of the CAD software, and draw the boundary line of the outer wall. At the same time, the contour lines of all appendages such as doors, windows and balconies also need to be carefully identified and drawn. This process requires the operator to have high graph recognition ability and drawing skills. Graph merging and area statistics: after completing the drawing of all single-wall and appendages, the operator needs to manually merge the scattered parts into a complete graph file. Finally, the operator manually selects the closed area for area calculation using the area calculation function of CAD, and finally manually summarizes the total area of the outer wall of the whole building. The main problems existing in the prior art are: the operation process is highly tedious and repetitive, the manual dependence is high, the efficiency is low, and the error risk is high. Therefore, the current outer wall area calculation method based on manual operation and general CAD software has the significant shortcomings of low efficiency, large workload, high error risk and difficult modification and maintenance when dealing with complex buildings. There is an urgent need for a more efficient, intelligent and highly automated outer wall area calculation method to improve the operation efficiency and data accuracy, reduce the labor cost and error risk, and meet the application requirements of the building industry. SUMMARY
[0004] The purpose of the present application is to solve at least one of the defects existing in the prior art, and to provide a building facade drawing method, system and storage medium based on SouthMap, which can effectively improve the drawing efficiency and accuracy, and reduce the manual dependence.
[0005] To achieve the above-mentioned purpose, in a first aspect, the present application provides a building facade drawing method based on SouthMap, which comprises the following steps: loading three-dimensional space data of a building to be drawn, and generating a three-dimensional viewport with the same size as a two-dimensional viewport, wherein the three-dimensional space data comprises at least one of point cloud data, a real scene triangular mesh model and a structured building model; receiving a sequence of house boundary points selected by a user in the three-dimensional viewport and automatically calculating the height H to generate a house range line L fw . according to the house range line L fwand height H, to generate the facade frame L with azimuth identification xh k ; activate the facade working state, and in response to the selection operation of the facade frame L k , perform: acquire the azimuth identification xh of the corresponding outer extension range line L through entity extension data, construct a three-dimensional clipping plane equation according to the house boundary points p1, p2 associated with the azimuth identification xh and the height H, drive the three-dimensional viewport to lock to the target wall surface, and apply a plane clipping algorithm to retain the target wall surface region; establish the projection relationship between the three-dimensional wall surface coordinates and the facade frame L k ; in response to the input operation of the user on the three-dimensional space data and the facade frame L k , generate the associated door and window component entity; identify the component entity generated in the facade mode, calculate the area of the component entity according to the azimuth identification xh, and generate a statistical report containing details and classified summary according to the area.
[0006] Further, the house boundary point sequence selected by the user on the three-dimensional viewport and automatic elevation calculation are received to generate the house range line L fw and the height H, specifically including: receive the house boundary point sequence selected by the user on the three-dimensional viewport to generate the house range line L fw ; based on the point set of the house range line, for any point P n (X, Y, Z) on the house range line L fw , construct a vertical line segment P n P t , wherein P t has the same X and Y coordinates as P n , but different Z values; use a scene intersection calculator to calculate the intersection set of the line segment P n P t and the three-dimensional space data; extract the Z coordinate extreme values of the intersection set as the maximum elevation H max and the minimum elevation H min , subtract the minimum elevation H max from the maximum elevation H min to obtain the height H.
[0007] Further, the house range line L fw and the height H are used to generate the facade frame L with azimuth identification xh k , specifically including: determining an outward expansion distance, generating an outward expansion range line L based on the outward expansion distance and the house range line L fw , generating an elevation frame L with an azimuth mark xh based on the length of the side of the outward expansion range line L and the house height H k , the width of the elevation frame L k is equal to the corresponding length of the side of the outward expansion range line L, and the height is equal to the house height H.
[0008] Further, based on the outward expansion distance and the house range line L fw , an outward expansion range line L is generated, specifically comprising: based on the outward expansion distance and the house range line L fw , using the original figure expansion method or the minimum outer rectangular expansion method, an outward expansion range line L is generated.
[0009] Further, the application plane clipping algorithm retains the target wall surface area, specifically comprising: Based on the house boundary points p1, p2 and the floor point p3, a plane equation of the target wall surface is constructed; Based on the plane equation, left and right side clipping planes perpendicular to the target wall surface are generated; Through the clipping function of the graphic rendering engine, three-face clipping of the front, left and right faces is performed on the three-dimensional space data, and the target wall surface area is obtained.
[0010] Further, the coordinate mapping unit stores the following mapping parameters: the coordinates of the house boundary points p1, p2, the house height H and the boundary point coordinates of the elevation frame L k ; and is used to execute a real-time conversion function of three-dimensional wall surface coordinates to the coordinates of the elevation frame L k .
[0011] Further, before the response to the user's input operation on the three-dimensional space data and the elevation frame L k , it further comprises: configuring a component parameter library, the component parameter library comprising feature types, codes and layer attributes; responding to component type selection and drawing mode instructions; through the coordinate mapping unit, mapping three-dimensional wall surface coordinates to the elevation frame L k , synchronously generating two-three-dimensional component entities.
[0012] Further, the drawing mode instruction comprises ordinary outlining or rectangular frame selection.
[0013] In order to achieve the above purpose, the application also provides a building elevation drawing system based on SouthMap, which is based on the method and comprises the following modules: Loading module: configured to load the three-dimensional spatial data of the building to be drawn and generate a three-dimensional viewport with the same size as the two-dimensional viewport. The three-dimensional spatial data includes at least one of point cloud data, real-scene triangulation model and structured building model. The first generation module is configured to receive the sequence of house boundary points selected by the user in the 3D viewport and perform automatic elevation calculations to generate the house boundary line L. fw and height H; The second generation module is configured to generate data based on the house boundary line L. fw And height H, generate an elevation frame L with orientation label xh. k ; The cropping module is configured to activate the facade working state and respond to the facade frame L. k The selected operation is executed as follows: obtain the orientation identifier xh of the corresponding outer expansion range line L through entity expansion data, construct a three-dimensional clipping plane equation based on the house boundary points p1 and p2 associated with the orientation identifier xh and the height H, drive the three-dimensional viewport to lock to the target wall, and apply the plane clipping algorithm to retain the target wall area. Projection module: configured to establish the three-dimensional wall coordinates and the elevation frame L through the coordinate mapping unit. k investment Shadow Relationship; Third Generation Module: Configured to respond to user input in the three-dimensional spatial data and the elevation frame L k On Input operations generate associated door and window component entities; The fourth generation module is configured to recognize the component entities generated in the facade mode, calculate the area of the component entities according to the orientation identifier xh, and generate a statistical report containing details and classification summaries based on the area.
[0014] In order to achieve the above objectives, in a third aspect, the present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described in the first aspect.
[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention improves the positioning efficiency of point clouds by automatically processing 3D data and co-generating 2D and 3D viewports; it uses intelligent generation of building outlines and coordinate mapping to draw components such as doors and windows, replacing the manual outlining and annotation used in existing technologies, thus ensuring a significant improvement in drawing efficiency; it uses automatic area statistics based on the orientation marker xh to avoid errors from manual merging and summarizing; and it uses 3D clipping plane equations to clip irregularly shaped walls, effectively improving drawing accuracy. Attached Figure Description
[0016] Figure 1 A flow chart of a SouthMap-based building facade drawing method according to Embodiment 1 of the present application; Figure 2 A system block diagram of a SouthMap-based building facade drawing system according to Embodiment 1 of the present application. DETAILED DESCRIPTION
[0017] For the purpose, technical solutions and advantages of the present application to be clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.
[0018] Embodiment 1 Please refer to Figure 1 A SouthMap-based building facade drawing method according to the preferred embodiment of the present application comprises the following steps: S1: loading three-dimensional space data of a building to be drawn, and generating a three-dimensional viewport with the same size as a two-dimensional viewport, wherein the three-dimensional space data comprises at least one of point cloud data, a real scene triangular mesh model and a structured building model; S2: receiving a sequence of house boundary points selected by a user in the three-dimensional viewport and automatically calculating an elevation, to generate a house range line L fw and a height H; S3: generating a facade frame L fw with an orientation identifier xh according to the house range line L k and the height H; S4: activating a facade working state, and in response to a selection operation of the facade frame L k , performing the following: obtaining an orientation identifier xh of a corresponding outer extension range line L through entity extension data, constructing a three-dimensional clipping plane equation according to house boundary points p1, p2 associated with the orientation identifier xh and the height H, driving the three-dimensional viewport to lock to a target wall surface, and applying a plane clipping algorithm to retain a target wall surface region; S5: establishing a projection relationship between three-dimensional wall surface coordinates and the facade frame L k through a coordinate mapping unit; S6: in response to an input operation of a user on the three-dimensional space data and the facade frame L k , generating associated door and window component entities; S7: identifying component entities generated in a facade mode, calculating areas of the component entities according to the orientation identifier xh, and generating a statistical report containing details and a classified summary according to the areas.
[0019] The embodiment is based on SouthMap software, and positioning efficiency of point cloud is improved through automatic processing of three-dimensional data and generation of two-three-dimensional viewports. The component such as door and window is drawn by using intelligent generation of house contour and coordinate mapping linkage, so that the drawing efficiency is effectively improved, manual edge drawing and marking in the prior art are replaced, and the drawing efficiency is effectively improved. The automatic area statistics based on the azimuth identifier xh avoids manual merging and summarizing errors. The three-dimensional cutting plane equation is used to cut the special-shaped wall surface, and the drawing precision is effectively improved.
[0020] In an optional embodiment, in step S1, the loaded three-dimensional space data includes at least one of point cloud data (.las format), a real scene triangular net model (.osgb format) and a structured building model (.xml format). The point cloud data is obtained by recording high-precision three-dimensional space coordinate information of a building to be drawn according to laser scanner emitting laser pulses and receiving reflection signals. The real scene triangular net model is obtained by obtaining a large number of overlapping images through oblique photography of a target region from multiple angles (usually five directions: downward, front, rear, left and right), and then performing three-dimensional reconstruction and texture mapping processing. The structured building model is obtained by performing parameterized design modeling in BIM (such as Revit, ArchiCAD) or CAD software, and then exporting structured model data containing geometry, attributes and associated relationships through a specific plug-in or software. Loading one of the three kinds of three-dimensional space data on the SouthMap software automatically activates viewport creation to generate a three-dimensional viewport with the same size as a two-dimensional viewport. The two-dimensional viewport is a drawing area provided by CAD, and the two-dimensional viewport handle can be obtained through the cad function acedGetAcadDwgView(), and the size of the two-dimensional viewport can be obtained through the mfc function GetRect() interface. The generated three-dimensional viewport compresses the original two-dimensional viewport, that is, the original two-dimensional viewport is equally divided to make the two-dimensional and three-dimensional viewports have the same size.
[0021] The embodiment automatically aligns the three-dimensional model coordinate system with the two-dimensional CAD origin, eliminates the manual positioning link, shortens the point cloud / model loading and positioning time, and also forces the three-dimensional viewport size to be equal to the two-dimensional viewport size, thereby providing a unified mathematical basis for subsequent space calculation, such as elevation intersection, coordinate mapping and area statistics, and being beneficial to improving the drawing precision.
[0022] In an optional embodiment, in step S2, the following steps are specifically included. S2.1: receiving a house boundary point sequence selected by a user on the three-dimensional viewport to generate a house range line L fw ; S2.2: based on the point set of the house range line, for any point P fw on the house range line L n(X, Y, Z), the vertical line segment P is constructed n P t , wherein P t has the same X, Y coordinates and different Z values as P n . S2.3: the scene intersection is used to calculate the line segment P n P t and the intersection set of the three-dimensional space data; in this embodiment, the scene intersection is the LineSegmentIntersector function of osg.
[0023] S2.4: the Z coordinate extreme value of the intersection set is extracted as the maximum elevation H max and the minimum elevation H min , the maximum elevation H max is subtracted from the minimum elevation H min , and the height H is obtained.
[0024] In this embodiment, through automatic elevation calculation and house contour line generation, higher precision calculation can be realized, a spatial reference for facade drawing is established, manual delineation distortion is eliminated, and contour data efficiency is improved.
[0025] In an optional embodiment, in step S3, specifically comprising: determining an outward expansion distance, generating an outward expansion range line L based on the outward expansion distance and the house range line L fw , generating a facade frame L k with a direction identifier xh based on the side length of the outward expansion range line L and the house height H, the width of the facade frame L k is equal to the corresponding side length of the outward expansion range line L, and the height is equal to the house height H.
[0026] Further, based on the outward expansion distance and the house range line L fw , an outward expansion range line L is generated, specifically comprising: based on the outward expansion distance and the house range line L fw , using the original figure expansion method or the minimum enclosing rectangle expansion method, an outward expansion range line L is generated.
[0027] For example, in the SouthMap software, the facade frame generation function is executed, the generated outward expansion range line L is selected, the facade frame outward expansion height is set (the default value is 5.0), then an optional point on the drawing is placed to generate the corresponding facade frame L k , the width of the facade frame is the distance between every two points (the side length) of the range line L, that is, the distance between P n and P n+1 , and the height is the drawing house line L fwheight H, the corresponding serial number xh is marked on each side of the range line L, and the frame L k is marked above the frame L
[0028] In this embodiment, by automatically generating the elevation frame with the orientation mark xh, it is beneficial to subsequently generate the area report by driving the xh mark, saves manual work, and has high accuracy.
[0029] In an optional embodiment, in step S4, specifically comprising: S4.1: constructing a plane equation of the target wall surface based on the house boundary points p1, p2 and the floor point p3; S4.2: generating left and right side clipping planes perpendicular to the target wall surface based on the plane equation; S4.3: performing three-face clipping of the front, left and right faces on the three-dimensional space data through the clipping function of the graphics rendering engine, to obtain the target wall surface region.
[0030] For example, the elevation parameter m bLm is set inside the SouthMap software, when the elevation parameter m bLm = True, the system enters the special state of elevation drawing, it can be understood that when m bLm = False, the system releases the three-dimensional viewport lock, removes the clipping plane, and restores the basic drawing function. Clicking the elevation frame L k generated by the two-dimensional viewport, through the pickfirstModified() function of the cad editing reactor (AcEditorReactor), the entity id can be obtained, and if m bLm is false, the selected operation is executed and ended, otherwise the information is continuously obtained, the serial number xh of the corresponding outer range line L is obtained through the entity id and the extension data, that is, the edge of the house range line L fw , through the point set of the range line L fw , the two points p1 and p2 of the corresponding edge can be obtained, through the point set of the range line L fwheight H, find the floor point p3 of p1, and determine a plane equation through three points (p1, p2, p3). The three-dimensional window jumps to the corresponding wall surface and locks through the osg perspective function and the plane equation, and finds the left and right plane equations of the wall surface through points p1, p2 and height H, and then uses the osg clipping function (setClipPlane) to clip the front, left and right of the wall surface in the three-dimensional model, leaving only the middle wall surface to be displayed. At the same time, pass points P1, P2, height H, the left lower corner point LP1 and the right lower corner point RP2 of the entity id to the designated class (FacadeBase) to store them, which will be used in subsequent calculation of three-dimensional and two-dimensional point coordinate conversion.
[0031] In an optional embodiment, in step S5, the coordinate mapping unit stores the following mapping parameters: the coordinates of the house boundary points p1, p2, the height H of the house, and the facade frame L k of the boundary point coordinates; and is used to perform a real-time conversion function of three-dimensional wall surface coordinates to the facade frame L k coordinates. In this embodiment, the real-time conversion function is FacadeBase:: remapMouse function.
[0032] For example, if the value of m bLm is false, it remains unchanged, and if it is true, the FacadeBase:: remapMouse function is called to convert the coordinates obtained during mouse movement to the corresponding two-dimensional frame L_k, so as to realize the relative position movement of the two-dimensional mouse in the corresponding frame when the three-dimensional mouse moves on the wall surface.
[0033] In an optional embodiment, before step S6, it further includes: configuring a component parameter library, the component parameter library including a feature type (door, bed, balcony, air conditioner hanging machine, etc. Custom entity), coding and layer attribute; responding to component type selection and drawing mode instruction; mapping three-dimensional wall surface coordinates to the facade frame L k, the two-dimensional and three-dimensional components are generated synchronously. The drawing mode instruction includes common edge drawing or rectangular frame selection. Common drawing is edge drawing according to a model, and rectangular drawing is two-point drawing, that is, from a top-left corner point to a bottom-right corner point (or from a bottom-left corner point to a top-right corner point). A point Pn is taken on a ground object in the three-dimensional viewport by using a mouse, a FacadeBase:: remapMouse function is called to calculate a two-dimensional point coordinate Pn_new projected into a corresponding frame in the two-dimensional viewport, and three-dimensional and two-dimensional synchronous drawing is started. Until drawing is completed, the entity generated in the three-dimensional viewport is projected into the corresponding frame in the two-dimensional viewport, the above steps are repeated to draw entities of the same type, or the operation is repeatedly performed to draw different ground objects. In the facade mode, the step S5 is repeatedly performed, that is, other facade frames L_k (corresponding to different walls) are clicked, and then the step S6 is performed to draw ground objects on the corresponding walls, until all drawings are completed.
[0034] In an optional embodiment, in the step S7, entities to be counted are selected, and a corresponding area counting table position is set by clicking any point, with detailed and classified summary information.
[0035] The embodiment is based on SouthMap software, and three-dimensional data automatic processing and two-dimensional and three-dimensional viewport cooperation generation are used, so that the positioning efficiency of point clouds is improved; house contour intelligent generation and coordinate mapping linkage drawing of doors and windows and other components are used to replace manual edge drawing and marking in the prior art, so that the drawing efficiency is effectively improved; automatic area counting based on the direction identifier xh is used to avoid manual merging and summary errors; a three-dimensional clipping plane equation is used to clip special-shaped walls, so that the drawing precision is effectively improved.
[0036] Embodiment 2 Please refer to Figure 2 The building facade drawing system based on SouthMap according to the embodiment of the application includes the following modules. A loading module is configured to load three-dimensional space data of a building to be drawn, and generate a three-dimensional viewport with the same size as a two-dimensional viewport, wherein the three-dimensional space data includes at least one of point cloud data, a real scene triangular mesh model and a structured building model; A first generation module is configured to receive a house boundary point sequence selected by a user in the three-dimensional viewport and automatically calculate an elevation, and generate a house range line L fw and a height H; A second generation module is configured to generate a facade frame L fw with a direction identifier xh according to the house range line L k ; A clipping module is configured to activate a facade working state, and respond to the facade frame L kThe selected operation is executed as follows: obtain the orientation identifier xh of the corresponding outer expansion range line L through entity expansion data, construct a three-dimensional clipping plane equation based on the house boundary points p1 and p2 associated with the orientation identifier xh and the height H, drive the three-dimensional viewport to lock to the target wall, and apply the plane clipping algorithm to retain the target wall area. Projection module: configured to establish the three-dimensional wall coordinates and the elevation frame L through the coordinate mapping unit. k investment Shadow Relationship; Third Generation Module: Configured to respond to user input in the three-dimensional spatial data and the elevation frame L k On Input operations generate associated door and window component entities; The fourth generation module is configured to recognize the component entities generated in the facade mode, calculate the area of the component entities according to the orientation identifier xh, and generate a statistical report containing details and classification summaries based on the area.
[0037] The system proposed in this embodiment is based on the method proposed in Embodiment 1. Therefore, the options proposed in Embodiment 1 are also applicable to this embodiment. To avoid repetition, they will not be described again here.
[0038] Example 3 This invention also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the method described in Embodiment 1.
[0039] The readable storage medium can be any available medium or data storage device that the processor can access, including but not limited to a magnetic storage (e.g., a floppy disk, a hard disk, a magnetic tape, a magneto-optical disk (MO), etc.), an optical storage (e.g., a compact disk (CD), a digital versatile disk (DVD), a Blu-ray disk (BD), a high-definition versatile disk (HVD), etc.), and a semiconductor storage (e.g., a read-only memory (ROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a NAND FLASH, a solid-state disk (SSD), etc.), etc.
[0040] Obviously, the above embodiments of the present application are merely exemplary and are not intended to limit the embodiments of the present application. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. All the embodiments are not required to be enumerated. Any modification, equivalent replacement, and improvement within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application.
Claims
1. A SouthMap-based building facade drawing method, characterized by, The method comprises the following steps: loading three-dimensional space data of a building to be drawn, and generating a three-dimensional viewport with the same size as a two-dimensional viewport, the three-dimensional space data comprising at least one of point cloud data, a real scene triangular mesh model, and a structured building model; Receiving a sequence of house boundary points selected by a user in the three-dimensional viewport and automatic elevation calculation, generating a house range line L fw and height H; According to the housing range line L fw and the height H, a facade frame L with an azimuthal identification xh is generated k ; activate the facade working state, and in response to selection operation of the facade frame L k , execute: acquire the orientation identifier xh of the corresponding outer extension range line L through entity extension data, construct a three-dimensional clipping plane equation according to the house boundary points p1, p2 associated with the orientation identifier xh and the height H, drive the three-dimensional viewport to lock to the target wall surface, and apply a plane clipping algorithm to retain the target wall surface region; The three-dimensional wall surface coordinates are established by a coordinate mapping unit to project relationship of the elevation frame L k ; in response to user input operation on the three-dimensional space data and the elevation frame L k , the associated door is generated a window component entity; identifying a component entity generated in a facade mode, calculating an area of the component entity according to the orientation identification xh classification, and generating a statistical report containing details and classification summaries according to the area.
2. The method of claim 1, wherein, The receiving user selects a sequence of house boundary points in the three-dimensional viewport and the automatic elevation calculation generates a house range line L fw and height H, specifically comprising: receiving a sequence of house boundary points selected by a user on the three-dimensional viewport, generating a house range line L fw ; Based on the point set of the house boundary line, for the house boundary line L fw The last point P n (X, Y, Z), a vertical line segment P n P t Where P t The X and Y coordinates of P n are the same, and the Z value is different; A scene intersection is used to compute the line segment P n P t set of intersection points with the three-dimensional spatial data; extracting the Z coordinate extreme values of the intersection set as the maximum elevation H max and the minimum elevation H min , the maximum elevation H max minus the minimum elevation H min to obtain the height H.
3. The method of claim 1, wherein, said according to the housing range line L fw and height H, to generate an elevation frame L with azimuth identification xh k , specifically comprising: determining an outward extension distance, generating an outward extension line L based on the outward extension distance and the house perimeter line L fw , generating an outward extension line L based on the outward extension distance and the house perimeter line L k , generating an elevation frame L with an azimuthal identification xh based on the length of the sides of the outward extension line L and the height H k , the width of the elevation frame L being equal to the corresponding length of the sides of the outward extension line L and the height being equal to the height H.
4. The method of claim 3, wherein, generate an extended range line L based on the extended distance and the house range line L fw , generate an extended range line L, specifically comprising: generating an extended range line L based on the extended distance and the house range line L fw , using a primitive shape extension method or a minimum outer rectangle extension method.
5. The method of claim 1, wherein, The application retains a target wall surface area by using a plane clipping algorithm, and specifically comprises the following steps: constructing a plane equation of the target wall surface based on the house boundary points p1 and p2 and the floor point p3; generating left and right side clipping planes perpendicular to the target wall surface based on the plane equation; performing front, left and right clipping on the three-dimensional space data by using a clipping function of a graphics rendering engine, so as to obtain the target wall surface area.
6. The method according to claims 1-5, characterized in that, The coordinate mapping unit stores the following mapping parameters: the coordinates of the house boundary points p1, p2, the height H and the facade frame L k boundary point coordinates; and is used to perform real-time conversion functions of three-dimensional wall surface coordinates to the facade frame L k coordinates.
7. The method of claim 1, wherein, Before the response to the user's input operation on the three-dimensional space data and the elevation frame L k , it also includes configuring a component parameter library, which includes the type of ground object, coding and layer attributes; responding to component type selection and drawing mode instructions; mapping three-dimensional wall coordinates to the elevation frame L k by the coordinate mapping unit, and synchronously generating two-dimensional and three-dimensional component entities.
8. The method of claim 7, wherein, The drawing mode instruction comprises ordinary sketching or rectangular frame selection.
9. A SouthMap-based building facade rendering system, said system being based on the method of any one of claims 1-8, characterized in that, The application comprises the following modules: a loading module configured to load three-dimensional space data of a building to be drawn, and generate a three-dimensional viewport with the same size as a two-dimensional viewport, the three-dimensional space data comprising at least one of point cloud data, a real scene triangular mesh model, and a structured building model; The first generating module is configured to receive the sequence of house boundary points selected by the user in the three-dimensional viewport and the automatic elevation calculation, and generate a house range line L fw and a height H. a second generating module configured to generate an elevation frame L fw with an azimuthal identification xh, according to said housing range line L k and the height H; The cutting module is configured to activate the facade working state, and in response to a selection operation of the facade frame L k , perform: obtaining an azimuth mark xh of a corresponding outer extension range line L through entity extension data, constructing a three-dimensional cutting plane equation according to house boundary points p1 and p2 associated with the azimuth mark xh and the height H, driving the three-dimensional viewport to lock to a target wall surface, and applying a plane cutting algorithm to retain a target wall surface region. The projection module is configured to establish a three-dimensional wall surface coordinate and the elevation drawing frame L by the coordinate mapping unit k of the projection module shadow relationship; a third generation module configured to generate, in response to a user input on the three-dimensional space data and the elevation frame L k input operation, and generating associated door and window component entities; a fourth generation module configured to identify a component entity generated in a facade mode, calculate an area of the component entity according to the orientation identification xh classification, and generate a statistical report containing details and classification summaries according to the area.
10. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by a processor to realize the steps of the method in any one of claims 1 to 8.