Three-dimensional building model dynamic damage modeling method based on multi-parameter coupling
Through the dynamic damage modeling method of three-dimensional building models based on multi-parameter coupling, the problems of inaccurate calculation efficiency and inaccurate simulation results in the existing technology are solved, and high-precision and high-efficiency building model damage simulation are achieved, which improves the credibility of military training and ammunition utilization rate.
Patent Information
- Application Number
- CN202411852247.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-16
- Publication Date
- 2025-03-25
AI Technical Summary
When the existing three-dimensional architectural model damage modeling method deals with complex scenarios and multiple parameter coupling effects, the calculation efficiency is low, making it difficult to accurately reflect the complex situation of multi-factor coupling in the real world, resulting in a large deviation between the simulation results and the actual damage effect.
A three-dimensional architectural model dynamic damage modeling method based on multi-parameter coupling is adopted to construct a crushing model through component model modeling and plane cutting algorithm of the building model. Combining physical principles and numerical simulation methods, a multi-parameter coupled damage model is established, and dynamic damage simulation is performed in the physics engine.
It improves modeling accuracy and computing efficiency, enhances the credibility of military simulation training, can quickly and in real time calculate the damage efficiency of building buildings under different attack conditions, improves ammunition utilization, and provides technical support for the formulation of combat plans.
Smart Images
Figure CN119692037A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of computer simulation, and in particular to a dynamic damage modeling method for a three-dimensional building model based on multi-parameter coupling. Background Art
[0002] As the current military struggle becomes increasingly serious, the damage simulation of target three-dimensional building models in the field of military training simulation has become more important. At present, most modeling methods only consider a single or a small number of parameters, which is difficult to accurately reflect the complex situation of multi-factor coupling in the real world. Therefore, it is of great practical value and application prospect to develop a three-dimensional building model damage modeling method that can integrate multiple parameters (such as material properties, structural form, external impact force, etc.) for coupling analysis.
[0003] In the existing 3D model damage research, most of them use traditional physical simulation or simplified mathematical models for prediction. These methods often ignore the comprehensive influence of key parameters such as model material, weight, thickness and elastic energy, resulting in a large deviation between the simulation results and the actual damage effect. At the same time, the existing technology has low computational efficiency when dealing with complex scenes and multiple parameter coupling effects, and it is difficult to meet the needs of actual applications. Summary of the invention
[0004] In view of the above analysis, the embodiment of the present invention aims to provide a dynamic damage modeling method for a three-dimensional building model based on multi-parameter coupling, which can realize the dynamic damage of a three-dimensional building model under the action of external forces (explosion, impact) in a virtual battlefield environment, and truly reflect the transformation process and results when the target building is hit. It is used to solve the problem that the damage effect of the existing damage modeling method is not realistic and the damage calculation efficiency is low in three-dimensional simulation.
[0005] The present invention provides a three-dimensional building model dynamic damage modeling method based on multi-parameter coupling, comprising the following steps:
[0006] Step 1: Building model fragmentation modeling: Establish a complete building model, cut the created model using a plane cutting algorithm, and thus construct a fragmented model;
[0007] Step 2: Parameter setting and coupling model establishment: define parameters, physical principles and numerical simulation methods, and establish a multi-parameter coupling damage model;
[0008] Step 3: Dynamic damage simulation, load the pre-made broken model into the physics engine for dynamic damage simulation.
[0009] Compared with the prior art, the present invention has the following beneficial effects:
[0010] (1) The present invention adopts a component-based modeling method and combines it with a plane segmentation algorithm to construct a fragmentation model. While improving the modeling accuracy, the credibility of military simulation training is greatly improved through the highly realistic damage simulation of the building model, which has extremely high military value.
[0011] (2) The present invention comprehensively considers the key parameters of the model, such as material, weight, thickness, etc., and combines the laws of Newtonian mechanics to construct the damage model. By constructing the topological relationship of the broken skin model to form a tree structure, the CPU calculation and rendering pressure after the model is optimized and controlled, thereby improving the model damage calculation efficiency and the visual effect of the model damage simulation;
[0012] (3) The present invention is applicable to combat mission scenarios such as ammunition attacking ground buildings. It can quickly and in real time calculate the damage effectiveness of ammunition on buildings under different attack conditions, which helps to obtain the best attack conditions of ammunition on targets, improve ammunition utilization, and provide technical support for formulating combat plans. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 Flowchart of dynamic damage modeling method for building models
[0014] Figure 2 Schematic diagram of component modeling of building models;
[0015] Figure 3 Building model segmentation modeling process;
[0016] Figure 4 Schematic diagram of planes cutting triangles when they intersect;
[0017] Figure 5 Schematic diagram of the relationship between the plane and the triangle when they do not intersect;
[0018] Figure 6 Schematic diagram of the new cut surface after reorganization;
[0019] Figure 7 Remove duplicate vertices;
[0020] Figure 8 Schematic diagram of the new cutting surface boundary;
[0021] Fig. 9 Rendering of the building being cut and shattered;
[0022] Fig.10 Schematic diagram of component surface pressure under external force;
[0023] Fig.11 The positional relationship between the ammunition and the bombed building walls;
[0024] Fig.12 Object damage flow based on physics engine
[0025] Fig.13 The hierarchical structure diagram after the geometric body is cut;
[0026] Fig.14 Fragment node connectivity graph;
[0027] Fig.15 Node connectivity graph of the entire model fragment;
[0028] Fig.16 Demonstration diagram of 3D building model damage simulation. DETAILED DESCRIPTION
[0029] The present invention provides a three-dimensional building model dynamic damage modeling method based on multi-parameter coupling, comprising the following steps:
[0030] Step 1: Architectural model fragmentation modeling:
[0031] The building model is split into multiple independent components according to elements such as walls, beams, columns, floors, doors, windows, etc., and then assembled according to design requirements to form a complete building model.
[0032] Step 1.1: Collect basic data of the building model: including design drawings, material specifications, structural parameters, etc.
[0033] Step 1.2: Preprocess the collected data: including data cleaning, format unification and necessary conversion.
[0034] Step 1.3: Create a 3D building model: Use professional 3D modeling software (such as Maya, 3DS Max, Revit, etc.) to create components. During the creation process, you need to define the component's geometry, material, and properties;
[0035] Step 1.4: Edit and modify the created components, including adjusting the component size, position, direction, material and other properties.
[0036] This example uses concrete buildings as an example. Figure 2 The following is a four-view model of a reinforced concrete two-story building. The overall external dimensions of the building are 22m×8m×6m, and the floor height is 3m. The building has a total of 188 components, including 40 columns, 62 beams, 24 floors, and 62 walls, all made of reinforced concrete. The dimensions and materials of the components are shown in the following table:
[0037] Table 1 The dimensions and materials of the building model components are shown in the following table:
[0038]
[0039] Step 1.5: Use plane cutting method to break up the model;
[0040] The created model is cut using a plane cutting algorithm to construct a broken model, such as Figure 3 As shown, the specific construction method is as follows:
[0041] Step 1.5.1: Import the model and collect the model mesh data through editing tools;
[0042] Step 1.5.2: Use the plane and each mesh's triangles to perform a cutting algorithm to calculate new vertex data;
[0043] Among them, the specific method of triangle plane cutting is:
[0044] 3D models are usually composed of many triangles, which together form the surface of the model. Plane cutting refers to using a plane to cut a triangular mesh into two parts. When a plane cuts a triangle, it is necessary to detect the positional relationship between the triangle and the plane (Line Lerp), as follows:
[0045] (a) If Line Lerp>0&&Line Lerp<1, that is, the triangle intersects with the plane, find the intersection point with the plane, cut the triangle and generate new vertices, as follows Figure 4 As shown;
[0046] The calculation formula of the triangle and plane position relationship is as follows:
[0047]
[0048] In formula (1), PlaneNormal represents the plane normal vector, Point represents a point in 3D space, LineStart represents the starting point of the line, and LineEnd represents the end point of the line. The size of LineLerp is obtained by performing a dot product operation on the two vectors.
[0049] The calculation formula for the position relationship between the intersection point and the plane is as follows:
[0050] PlaneSide=Dot(PlaneNormal,Point-PlanePoint) (2)
[0051] In formula (2), PlaneSide represents the positional relationship between the point and the plane, PlaneNormal represents the plane normal vector, Point represents the same meaning as above, and PlanePoint represents any point on the plane. The position of the point relative to the plane is calculated by taking the product of two point vectors. When PlaneSide is positive, the point is located on the front of the plane, when PlaneSide is negative, the point is located on the back of the plane, and when PlaneSide is zero, the point is exactly on the plane.
[0052] (b) When the triangle does not intersect the plane, keep it as it is, as follows Figure 5 shown.
[0053] Step 1.5.3: Reconstruction of new cutting surfaces; the new vertex data will generate new mesh cutting surfaces (caps); therefore, an algorithm is needed to reconstruct these caps. The specific method is as follows:
[0054] (a) Convert the newly generated vertices to a 2D plane, select the reference point A, and then do a dot product between the vector connecting each point and A and the Y axis, and use the results to sort, such as Figure 6 shown.
[0055] (b) Remove duplicate vertices (same or similar dot product results), such as Figure 7 shown.
[0056] Among them, there are duplicate vertices in the area where C and D are located, and the duplicate vertices are removed.
[0057] Step 1.5.4: Determine the boundary of the new cutting surface and calculate the boundary UV vertex coordinates;
[0058] UV coordinates, also known as texture coordinates, are used to determine how points on a texture image are mapped to vertices on a 2D plane. Figure 8 The quadrilateral (Bound) shown in the figure must first determine the vertex positions of the quadrilateral, usually expressed as (x, y). The U coordinate represents the normalized value of the difference between the vertex's x coordinate and the quadrilateral's minimum x coordinate and maximum x coordinate. The V coordinate represents the normalized value of the vertex's y coordinate and the difference between the quadrilateral's minimum y coordinate and maximum y coordinate.
[0059] The UV coordinate calculation formula for each vertex of the quadrilateral is as follows:
[0060]
[0061] Where ver.X and ver.Y are the x and y coordinates of the vertex, and Bound.minX, Bound.maxX, Bound.minY, and Bound.maxY are the minimum and maximum x and y coordinates of the quadrilateral bounding box.
[0062] Step 1.5.5: Finally, combine the cap and the generated mesh surface to generate the final fragment mesh.
[0063] The effect after the architectural model cutting is completed is as follows Fig. 9 shown.
[0064] Step 2: Parameter setting and coupling model establishment;
[0065] Step 2.1: Parameter definition: Clarify the key parameters required for damage modeling, such as material parameters (elastic modulus E, density ρ), structural parameters (weight (W), thickness (T)) and control parameters (direct damage value (Hit), indirect damage value (indirectHit)).
[0066] 1) Material parameters include:
[0067] Elastic modulus E: reflects the ability of different materials to resist elastic deformation.
[0068] Density ρ: affects the mass and inertia of the material.
[0069] 2) Structural parameters include:
[0070] Weight W: affects the kinetic energy and potential energy of the structure during the damage process.
[0071] Thickness T: determines the bending stiffness and compressive resistance of the structure.
[0072] Step 2.2: Coupling model establishment: Based on the component parameters of the above building model, combined with physical principles and numerical simulation methods, a multi-parameter coupling damage model is established. The model should be able to consider the mutual influence between different parameters, such as the influence of material parameters on energy absorption and stress distribution, and the influence of weight and thickness on structural stability.
[0073] Step 2.2.1: Calculation of component surface load pressure;
[0074] The calculation formula of equivalent load pressure of the construction surface is simplified, and the peak pressure function P(x,y) of the construction surface is as follows:
[0075]
[0076] 0≤x≤L / 2,0≤y≤L / (2a)
[0077] Where L is the size of the long side of the structure, a is the aspect ratio of the structure, P1 is the peak pressure at the center of the structure, P2 is the peak pressure at the intersection A of the yield line and the long side of the component, P3 is the peak pressure at the intersection B of the yield line and the short side of the component, and P4 is the peak pressure at the corner C of the component.
[0078] Assuming that the virtual work done by the uniformly distributed load and the non-uniformly distributed load is equal under overpressure and displacement conditions, the equivalent uniformly distributed load Pu can be obtained as:
[0079] Pu=(2P1+2P2+P3+P4) / 6 (6)
[0080] The above formula shows that the equivalent uniformly distributed load has nothing to do with the aspect ratio of the reinforced concrete slab, but is only related to the overpressure load at the four characteristic points. In the case of a long-distance explosion, the overpressure at the four characteristic points p1≈p2≈P3≈p4 can be regarded as a uniformly distributed load P1 acting on the slab, thus Pu=P1.
[0081] Therefore, for components with a large length-to-width ratio, such as beams and columns, the above method can also be used to calculate the equivalent load pressure. The yield line of the beam and column is parallel to the short side. At the same time, the width of the beam and column is much smaller than the length, and the thickness of the beam is relatively large. It can be approximately considered that the load pressure is evenly distributed along the width of the beam surface, that is, P1 = P2, P3 = P4. The equivalent load pressure Pu is obtained as:
[0082] Pu=(2P1+P3) / 3 (7)
[0083] Among them, P1 is the peak pressure at the center of the beam, and P3 is the peak pressure at the edge of the beam.
[0084] Step 2.2.2: Calculation of component protection value;
[0085] Taking reinforced concrete buildings as an example, assuming that the equivalent load pressure Pu in step 2.2.1 is added to the surface of the component, the calculation of the component protection value can be described by the elastic modulus. The present invention uses the bulk modulus to describe the elastic properties of the component during volume deformation. The calculation formula is as follows:
[0086] armor=Pu / (V×ΔV / V) (8)
[0087] Where armor represents the protection value, Pu is the force acting on the surface of the component, V is the volume of the component, and ΔV is the change in the volume of the component.
[0088] When the impact force on a component is greater than the maximum resistance, the component is considered damaged. Based on the above description, a brief calculation of damage modeling is performed by taking an armor-piercing projectile hitting a building as an example. When the ammunition hits the building, assuming that the trajectory does not deflect during the movement of the ammunition, the position relationship between the ammunition and the bombed building wall is:
[0089] Assuming the actual penetration depth is H1, if The ammunition fails to penetrate the structure. When , it means that the ammunition can penetrate the component, where h1 is the thickness of the building wall.
[0090] Assuming the wall penetration coefficient is PT and the armor-piercing projectile body aspect ratio coefficient is C, the calculation model of the velocity reduction D caused by the actual penetration depth is established as follows:
[0091] D=H1.PT / C (9)
[0092] When the velocity reduction D of penetrating the target is less than the impact point velocity S, it means that the armor-piercing projectile has not penetrated the target, and the kinetic energy of the armor-piercing projectile is completely absorbed by the target. The mathematical calculation model of the generated energy factor E is as follows:
[0093]
[0094] Where E is the energy factor, S is the impact speed, and S l is the critical velocity of the armor-piercing projectile.
[0095] When the reduction amount D of penetrating the target is greater than or equal to the impact speed S, it means that the armor-piercing projectile penetrates the target, and part of the kinetic energy of the armor-piercing projectile is absorbed by the target. The mathematical calculation model of the generated energy factor E is as follows:
[0096]
[0097] In the formula, S n is the current strike speed. The data calculation model of the damage value dirDam generated by a single armor-piercing projectile is as follows:
[0098] dirDam=Hit.E (12)
[0099] Assuming Hit is the direct damage value of the armor-piercing projectile, and armor is the protection value (anti-deformation ability) of the building wall, the damage degree coefficient β model of the hit target is established as follows:
[0100] β=armor / dirDam (13)
[0101] When β<1, it indicates that the object being struck is damaged, and when β≥1, it indicates that the object being struck is not damaged.
[0102] Step 3: Dynamic damage simulation based on physics engine;
[0103] After the model is broken and cut, it is loaded into the physics engine for dynamic damage simulation, which includes the topological relationship construction after the geometry is cut, model collision detection and topological relationship calculation and update. The dynamic damage process based on the physics engine is as follows: Fig.12 shown.
[0104] Step 3.1: Topological relationship construction after geometry cutting
[0105] Take the wall of the building model as an example. Fig.13 The cut wall shown consists of a total of 8 fragments, divided into four levels:
[0106] Debris0 is the complete unbroken fragments, defined as level 0;
[0107] Debris1 and Debris2 are the fragments of Debris0, defined as level 1;
[0108] Debris3 and Debris4 are the fragments of Debris1, which are defined as level 2;
[0109] Debris5, Debris6, and Debris7 are the fragments of Debris2, defined as level 3;
[0110] Debris3-7 can no longer be broken.
[0111] The hierarchical structure is Fig.14 , which is a tree structure. The tree structure can well control the CPU calculation and rendering pressure after fragmentation.
[0112] Debris3-7 is the leaf node of Debris. According to the coplanar information of the cutting surfaces between nodes, a fragment connectivity graph can be generated. The graph contains node information and edge information, where the edge information includes edge length and edge connectivity value. The edge connectivity value indicates whether the connection edge is easy to be destroyed. When the connectivity value is less than 1, it means that the connection is disconnected. If the connected component of a fragment graph is disconnected during runtime, the destroyed body will become two fragments.
[0113] After the model is cut into complex destructive bodies, its connectivity graph is also extremely complex, such as Fig.15 shown.
[0114] Step 3.2: Model entity collision detection;
[0115] 1) Rough judgment of collision: quickly determine which bounding boxes may intersect through hierarchical bounding boxes (OBBs), thereby quickly screening out pairs of objects that may collide;
[0116] 2) Accurate detection of collisions: Use the GJK algorithm to detect whether the objects actually intersect. Once a collision is detected, the collision point, collision normal, and collision depth information are calculated, and the state (speed, position) of the object is updated based on this information;
[0117] 3) Establish constraints: Convert the detected component positions, behaviors, and relationships into a Jacobian matrix that the algorithm can process, which is used to update variables or determine whether constraints are satisfied.
[0118] Step 3.3: Topological relationship calculation and update;
[0119] (1) Connectivity Break Calculation
[0120] The fragment connection diagram describes the static destruction body hierarchy. When the destruction body is subjected to force, the destroyed fragments are calculated through Connectivity Break.
[0121] Assume that a dynamic rigid body collides with a destructible body. The collision point and collision force are calculated by the physics engine using information such as position, velocity, and mass. The specific steps are as follows:
[0122] 1) Obtain the collision contact points between objects from all mainfolds information (a collection of all contact points or contact surfaces) in the physical collision detection results;
[0123] 2) Set the mass and velocity of the dynamic rigid body, assume that the destructible body is hit by a certain force (Force) at a certain impact point (HitPoint), and calculate the force at each point generated by the collision;
[0124] 3) Calculate the connectivity value of the leaf node and the adjacent nodes according to formula (13), that is, the damage coefficient β of the hit target;
[0125] 4) According to the Force (each weapon can be configured with a different Force), the fragments that need to be broken are traversed and calculated. If the fragment force threshold is exceeded, that is, β < 1, the fragment is broken, the old rigid body is deleted, and a new rigid body is created;
[0126] (2) Update the state of the model;
[0127] 1) Solve all generated Jacobian matrices uniformly and update the position and velocity of the object;
[0128] 2) Get detailed information of all fragments through the callback function and update the position and orientation of the current fragment;
[0129] 3) The calculation results of the connection fracture are virtually demonstrated through the visual simulation platform, including crack generation, structural deformation, partial collapse and other phenomena. The simulation demonstration screen is as follows Fig.16 shown.
Claims
1. A dynamic damage modeling method for a three-dimensional building model based on multi-parameter coupling, characterized in that: The specific steps are as follows: Step 1: Building model fragmentation modeling: Establish a complete building model, cut the created model using a plane cutting algorithm, and thus construct a fragmented model; Step 2: Parameter setting and coupling model establishment: define parameters, physical principles and numerical simulation methods, and establish a multi-parameter coupling damage model; Step 3: Dynamic damage simulation, load the pre-made broken model into the physics engine for dynamic damage simulation.
2. The method for dynamic damage modeling of a three-dimensional building model based on multi-parameter coupling according to claim 1 is characterized in that: In step 1, the specific steps are: Step 1.1: Collect basic data of the building model; Step 1.2: Preprocess the collected data; Step 1.3: Create a 3D building model: Use professional 3D modeling software to create components. During the creation process, you need to define the component's geometry, material, and properties; Step 1.4: Edit and modify the created components, including adjusting the component size, position, direction and material properties; Step 1.5: Use plane cutting method to break up the model.
3. The method for dynamic damage modeling of a three-dimensional building model based on multi-parameter coupling according to claim 2 is characterized in that: In step 1.5, the specific method of model fragmentation construction is: Step 1.5.1: Import the model and collect the model mesh data through editing tools; Step 1.5.2: Use the plane and the triangles of each mesh to perform a plane cutting algorithm to calculate new vertex data; Step 1.5.3: Reconstruction of new cutting surfaces; the new vertex data will generate new mesh cutting surfaces; therefore, an algorithm is needed to reconstruct these cutting surfaces; Step 1.5.5: Finally, combine the cut surface and the generated mesh surface to generate the final fragment mesh.
4. The method for dynamic damage modeling of a three-dimensional building model based on multi-parameter coupling according to claim 3 is characterized in that: In step 1.5.2, the specific method of triangle plane cutting is: 3D models are usually composed of many triangles, which together form the surface of the model. Plane cutting refers to using a plane to cut a triangular mesh into two parts. When a plane cuts a triangle, it is necessary to detect the positional relationship between the triangle and the plane. The details are as follows: (a) If Line Lerp>0&&Line Lerp<1, the triangle intersects with the plane. Find the intersection point with the plane, cut the triangle and generate a new vertex. The calculation formula of the triangle and plane position relationship is as follows: In the formula, PlaneNormal represents the plane normal vector, Point represents a point in 3D space, LineStart represents the starting point of the line, and LineEnd represents the end point of the line. The value of LineLerp is obtained by performing a dot product operation on the two vectors. The calculation formula for the position relationship between the intersection point and the plane is as follows: PlaneSide=Dot(PlaneNormal,Point-PlanePoint) In the formula, PlaneSide represents the positional relationship between the point and the plane, PlaneNormal represents the plane normal vector, Point represents the same meaning as above, PlanePoint represents any point on the plane, and the position of the point relative to the plane is calculated by taking the product of two point vectors; when PlansSide is positive, the point is on the front of the plane, when PlaneSide is negative, the point is on the back of the plane, and when PlaneSide is zero, the point is exactly on the plane; (b) When the triangle does not intersect the plane, it remains as is.
5. The method for dynamic damage modeling of a three-dimensional building model based on multi-parameter coupling according to claim 3 is characterized in that: In step 1.5.4, the UV coordinate calculation formula for each vertex of the quadrilateral is as follows: Where U is the normalized value of the difference between the vertex's x coordinate and the quadrilateral's minimum and maximum x coordinates, V is the normalized value of the difference between the vertex's y coordinate and the quadrilateral's minimum and maximum y coordinates, ver.X and ver.Y are the vertex's x and y coordinates, and Bound.minX, Bound.maxX, Bound.minY, and Bound.maxY are the minimum and maximum x and y coordinates of the quadrilateral's bounding box.
6. The method for dynamic damage modeling of a three-dimensional building model based on multi-parameter coupling according to claim 1, characterized in that: The specific steps in step 2 are: Step 2.1: Parameter definition: Identify the key parameters required for damage modeling; Step 2.2: Establishment of coupling model: Based on the component parameters of the above building model, combined with the principles of physics and numerical simulation methods, a multi-parameter coupling damage model is established.
7. The method for dynamic damage modeling of a three-dimensional building model based on multi-parameter coupling according to claim 6, characterized in that: The specific steps in step 2.2 are: Step 2.2.1: Calculation of component surface load pressure; Step 2.2.2: Calculation of component protection value.
8. The method for dynamic damage modeling of a three-dimensional building model based on multi-parameter coupling according to claim 7, characterized in that: Step 2.2.2: Calculation of component protection value; The protection value calculation formula is as follows: armor=Pu / (V×ΔV / V) Where armor represents the protection value, Pu is the force acting on the surface of the component, V is the volume of the component, and ΔV is the change in the volume of the component; The data calculation model of the damage value dirDam generated by a single armor-piercing projectile is as follows: dirDam=Hit.E In the formula, let Hit be the direct damage value of the armor-piercing projectile, armor be the protection value of the building wall, then the damage degree coefficient β model of the hit target is established as follows: β=armor / dirDam When β<1, it indicates that the object is damaged; when β≥1, it indicates that the object is not damaged.
9. The method for dynamic damage modeling of a three-dimensional building model based on multi-parameter coupling according to claim 1, characterized in that: The specific steps in step 3 are: Step 3.1: Construct topological relationship after cutting the geometry; Step 3.2: Model entity collision detection; specifically: rough judgment of collision, precise detection of collision, and establishment of constraint conditions; Step 3.3: Topological relationship calculation and update.
10. The method for dynamic damage modeling of a three-dimensional building model based on multi-parameter coupling according to claim 8, characterized in that: In step 3.3, specifically: (1) Connection fracture calculation Assume that a dynamic rigid body collides with a destructible body. The collision point and collision force are calculated by the physics engine through position, velocity, and mass information. The specific steps are as follows: 1) Obtain the collision contact points between objects from the set of all contact points or contact surfaces in the physical collision detection results; 2) Set the mass and velocity of the dynamic rigid body, assume that the destructible body is hit by a force at a certain impact point, and calculate the force at each point generated by the collision; 3) Calculate the connectivity value between the leaf node and the adjacent nodes, that is, the damage degree coefficient of the hit target; 4) Traverse and calculate the fragments that need to be disconnected. If the fragment force threshold is exceeded, the fragments are broken, the old rigid body is deleted, and a new rigid body is created; (2) Update the state of the model; 1) Solve all generated Jacobian matrices uniformly and update the position and velocity of the object; 2) Get detailed information of all fragments through the callback function and update the position and orientation of the current fragment; 3) The calculation results of the connection fracture are virtually demonstrated through the visual simulation platform.