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CN-121502893-B - Building design modeling method and system based on parameter entity and Boolean relation thereof

CN121502893BCN 121502893 BCN121502893 BCN 121502893BCN-121502893-B

Abstract

The invention discloses a building design modeling method and system based on parameter entities and Boolean relations thereof, wherein the method is to convert a plurality of building components into geometric data based on structural shapes respectively, and abstract the construction process from a single geometric body to an integral model according to the Boolean relations among the building components required by the design; the method comprises the steps of preprocessing building design related component data given by a user, redefining a geometric body by adopting a two-stage structure, storing the geometric body, representing a Boolean relation among components by a tree structure, transmitting the preprocessed data into a grid generation solver, and obtaining a final three-dimensional model and attached topology information through background grid and isosurface construction, topology information integration and grid post-processing. The method can ensure that the building design modeling process has better robustness and calculation efficiency.

Inventors

  • WANG ZHICHENG
  • LI MING

Assignees

  • 浙江大学

Dates

Publication Date
20260512
Application Date
20260113

Claims (9)

  1. 1. A building design modeling method based on parameter entity and Boolean relation thereof is characterized in that the method is characterized in that a plurality of building components are respectively converted into geometric data based on structural shape, and a construction process from a single geometric body to an integral model is abstracted according to the Boolean relation between the building components required by design, and the method specifically comprises the following steps: firstly, preprocessing building design related component data given by a user, wherein the preprocessing comprises redefining a geometric body by adopting a two-stage structure, storing the geometric body, representing a Boolean relation among components by a tree structure, storing by adopting a linked list structure during input processing, and converting the linked list structure into a continuous structure for storing when grid is generated; The input data after pretreatment is further transmitted into a grid generation solver, and a final three-dimensional model and attached topology information are obtained after three steps of background grid and isosurface construction, topology information integration and grid post-treatment; The two-stage structure is redefined in the geometry body to be a bottom layer and a top layer, wherein the bottom layer is a sub-curved surface, each sub-curved surface at least comprises a pointer to a data cache pool, an affine transformation matrix and a pointer to an inverse matrix of the affine transformation matrix on the data structure, meanwhile, the sub-curved surface is statically defined to be a parameter curved surface or an implicit curved surface, each sub-curved surface is required to provide a functional interface comprising a mapping and inverse mapping of a signed distance field, a signed distance field gradient, a three-dimensional Cartesian space to a curved surface parameter space, the top layer is the geometry body and is a space surrounded by a series of sub-curved surfaces, namely, the boundary of the geometry body is the union of a sub-curved surface set, and meanwhile, the geometry body keeps an axis alignment bounding box for reflecting the approximate boundary information of the whole geometry body.
  2. 2. The building design modeling method based on parameter entities and their boolean relationships according to claim 1, characterized in that degeneracy storage is performed in the case of overlapping sub-surfaces in three-dimensional space, with tolerance hash coding using affine transformation matrices for each sub-surface type to ensure that an infinite or self-closing surface always holds only a single instance, whose pointing is recorded simultaneously when storing pointers of sub-surface instances in geometry.
  3. 3. The building design modeling method based on the parameter entity and the Boolean relation thereof according to claim 1, wherein the building design modeling method is characterized in that a linked list structure is adopted for storage during input processing, specifically, a linked list structure is adopted for storing a Boolean operation tree node in operation, each node on the tree holds a pointer pointing to a father node or a child node, and the outermost side can inquire any other pointer only by holding any effective node pointer on the tree; Converting the linked list structure into a continuous structure during grid generation and calculation, and simultaneously directly storing a geometric node index set, geometric objects, sub-curved surface pointers and mapping relations so as to facilitate the traversal and access of the grid generation stage, specifically, converting a run-time Boolean operation tree into a calculation-time Boolean operation tree in two steps, firstly performing depth-first traversal on the run-time Boolean operation tree once, reversely constructing a sequence of nodes arranged according to a subsequent traversal sequence, and simultaneously extracting the index set of leaf nodes in the node sequence and all geometric objects related to the leaf nodes Is set of (a) Geometric body All of the sub-surfaces involved Is set of (a) Then execute one time of pairing Is de-duplicated and reformed at the same time as de-duplication Managed (managed) To the point of The mapping relation of (a), Subordinate to To the point of Is a mapping relation in the map.
  4. 4. The method for modeling architectural design based on parametric entity and Boolean relation thereof according to claim 1, wherein the constructing of the background grid and the iso-surface specifically comprises generating an axis-aligned uniform tetrahedral grid as the background grid in a limited space, sampling the signed distance field of each sub-surface at each grid point, and then incrementally constructing the approximate iso-surface of the sub-surface in each background grid unit using a linear interpolation method, thereby extracting the approximate grid of the sub-surface.
  5. 5. The building design modeling method based on the parameter entity and the Boolean relation thereof according to claim 4, wherein the topology information integration comprises the steps of gradually integrating a higher-level topology structure by adopting a simple topology analysis method according to the property of the existing geometric elements until the whole limited space is divided into a series of closely arranged subareas, specifically, from the connectivity and the property of an approximate isosurface network, adopting breadth-first traversal to integrate continuous approximate curved surface areas belonging to the same curved surface instance and approximate intersecting lines among different curved surface instances, sorting the adjacent relation of the continuous curved surface areas on the basis, and obtaining the closely arranged space subareas after the adjacent relation of a shell layer formed by the continuous curved surface areas is determined by additional topology ray tracking.
  6. 6. The building design modeling method based on the parameter entity and the Boolean relation thereof according to claim 5, wherein the grid post-processing specifically comprises the steps of connecting a boundary shell layer of the subarea with the inner and outer parts of the sub-curved surface, and extracting a required subarea in traversal based on data of a Boolean operation tree so as to form an output model.
  7. 7. A building design modeling system based on parametric entities and their boolean relationships, characterized by being adapted to implement the method of any of claims 1-6.
  8. 8. An electronic device, comprising: one or more processors; A memory for storing one or more programs; The one or more programs, when executed by the one or more processors, cause the one or more processors to implement the method of any of claims 1-6.
  9. 9. A computer readable storage medium storing computer executable instructions which, when executed, are adapted to carry out the method of any one of claims 1-6.

Description

Building design modeling method and system based on parameter entity and Boolean relation thereof Technical Field The invention belongs to the field of computer aided design and manufacture, and relates to a building design modeling method and system based on a parameter entity and a Boolean relation thereof. Background Computer aided design (Computer AIDED DESIGN, CAD) is an application science that incorporates many disciplines of mathematics, computers, etc., and is focused on studying how to construct and process geometries. CAD technology has been widely used in design and production links of various manufacturing industries because of its advantages of controllability, accuracy, intuitiveness, high efficiency, etc. At present, the technology has become an important component in the fields of mechanical engineering, electronic engineering, civil engineering, aerospace, animation games and the like. CAD kernels are a class of software components that are essentially the computational cores and geometry engines of CAD software. The CAD kernel encapsulates the core algorithms and data structures for handling geometry, providing a solid geometric modeling basis for upper CAD applications. A mature CAD kernel generally has the capabilities of generating and expressing curved surfaces, constructing solid models, implementing geometric transformations (moving, rotating, scaling) and complex boolean operations (union, intersection, difference set), handling topological relationships between geometric entities, and the like. In architecture, CAD kernels generally adopt an object-oriented design concept, and abstract complex geometric operations into callable programming interfaces by defining classes (e.g., points, lines, planes, volumes) and methods (e.g., intersection, stitching). This enables developers to directly utilize these optimized underlying functions in a specific programming environment, thereby significantly reducing the effort from zero development, ensuring excellent performance and stability of the final application when dealing with complex designs. As an application field of CAD software systems, building design requires modeling of the appearance and basic structure of a building, which involves a large-scale complex surface modeling scenario, which requires that the corresponding CAD kernel provide surface and curve modeling capabilities with better performance and accuracy. Meanwhile, boolean operation among a large number of geometric entities is also involved in building design, such as a situation that windows are installed on walls in a punching mode. Considering that many entities have boundaries in the form of surfaces or curves, CAD software systems also need to ensure that the boolean operations of these entities are correct, which requires robust boolean operation processing capabilities in the CAD kernel. Through decades of development, CAD curved surface modeling forms a geometric theory system which mainly comprises two representation modes of NURBS parameter curved surfaces and implicit curved surfaces and three processing methods of interpolation, fitting and approximation. Meanwhile, the independent curved surfaces often form an integral model through complex Boolean operation, so that the model water tightness and the calculation efficiency of the Boolean operation technology have a critical influence on the stability and the reliability of the three-dimensional modeling capability. NURBS parametric surfaces are difficult to handle complex boolean operations watertight because of the need to cross-calculate NURBS parametric surfaces when doing such operations, which is very challenging to improve their accuracy, stability and efficiency at the same time. The implicit curved surface is defined by the signed distance from a point in space to the nearest surface, so that the implicit curved surface has the characteristics of clear internal and external distinction, convenience in determining geometric boundaries and good mathematical properties. The method ensures that the curved surface is visual and clear in complex Boolean operation treatment, and can ensure the water tightness of the model under the condition that the curved surface is well defined. When modeling problems based on implicit surfaces and Boolean operations are processed, one effective method is to discretize and polygon the implicit surfaces under a given spatial range and accuracy, so as to construct a network with definite geometry and topology. In this type of method, some researchers choose to construct an explicit background grid first, consider the implicit surfaces one by one, subdivide the background grid by using the function definition of the implicit surfaces (for example Bagley B, Sastry S P, Whitaker R T. A Marching-tetrahedra Algorithm for Feature-preserving Meshing of Piecewise-smooth Implicit Surfaces[J]. Procedia Engineering, 2016, 163: 162-174 and Guo J, Wang X, Wang J, et al. Three-dimensi