CN-121997420-A - Implicit expression and rendering method and device of reinforcement model and storage medium

CN121997420ACN 121997420 ACN121997420 ACN 121997420ACN-121997420-A

Abstract

The invention discloses an implicit expression and rendering method and device of a reinforcement model and a storage medium, and belongs to the field of BIM. The method comprises analyzing IFC file of the reinforcement model, obtaining global coordinate information and combination information of each single reinforcement in the reinforcement model according to relative coordinates and combination information between layers, setting object space coordinate system of cube grid as coordinate system of implicit expression of the reinforcement model, defining ray equation as Combining the sweep path and the ray equation of a single steel bar, executing intersection test of rays and the single steel bar in a shader, changing fragment coloring according to intersection result, obtaining a visual result of implicit expression of a steel bar model after pipeline mixing, As a starting point for the ray, As the direction in which the radiation is advanced, Is a parameter of the ray. The working efficiency of BIM software is improved, and the requirement of a user on visual expression of the steel bar model is met.

Inventors

WAN LIN
ZENG ZHILIANG
CHEN WEIYA
SONG YUCHEN

Assignees

华中科技大学

Dates

Publication Date: 20260508
Application Date: 20260123

Claims (8)

1. The implicit expression and rendering method of the reinforcing bar model is characterized by comprising the following steps of: Acquiring and analyzing an IFC file of a reinforcing bar model to obtain a space coordinate system level corresponding to the reinforcing bar model, and sequentially superposing relative coordinates among the levels according to the combination information to obtain global coordinates of each single reinforcing bar in the reinforcing bar model; Setting an object space coordinate system of a cube grid as an implicit expression coordinate system of the steel bar model, expressing global coordinates of the single steel bar as space coordinates of two endpoints of a cylinder under the coordinate system, and constructing a corresponding implicit expression equation in the space of the cube grid according to classification and combination information of the steel bar model, wherein the single steel bar in the steel bar model takes the two endpoints of the cylinder as vectors, and the radius of the cylinder The method comprises the steps of taking a combined steel bar as a scalar, carrying out implicit expression by combining combined information on the basis of a single steel bar, wherein the radius parameter of the implicit expression corresponds to 1/2 of the diameter of the steel bar in the steel bar model, and the sweep path parameter corresponds to the axis track of the steel bar; Defining the ray equation as Combining the sweep path and the ray equation of the single steel bar, executing intersection test of rays and the single steel bar in a colorant, traversing all the single steel bars in the steel bar model in sequence, judging whether an implicit graphic element is hit or not according to the intersection test result of the single steel bar, mixing a plurality of judgment results to obtain a visual result of implicit expression of the steel bar model, As a starting point for the ray, As the direction in which the radiation is advanced, Is a parameter of the ray.
2. The method of claim 1, wherein the spatial coordinate system is hierarchical, comprising sequentially hierarchical in a building coordinate system, a floor coordinate system, and a physical coordinate system.
3. The method of claim 1, wherein the classification of the rebar model comprises: And dividing the steel bar model into single steel bars and combined steel bars according to the number of the single steel bars in the steel bar model, and classifying the combined steel bars into net-shaped steel bars and column-shaped steel bars.
4. The method of claim 3, wherein said implicitly expressing within the space of the cube grid further comprises: and implicitly expressing the mesh steel bars and the columnar steel bars according to the implicit expression of the single steel bars in the steel bar model and the combined information of the single steel bars in the mesh steel bars and the columnar steel bars.
5. The method of claim 1, wherein the sweep path is: Wherein, the Is the origin coordinates of the cylinder axis, For the end point coordinates of the cylinder axis, parameters Satisfy the following requirements Corresponding to the effective range of the axis of the reinforcing steel bar.
6. A method according to claim 3, characterized in that in said intersection test, it comprises: in the intersection test calculation process of the combined steel bars, a group of steel bars which are arranged in parallel are extracted from the combined steel bars to serve as candidate steel bars, wherein the candidate steel bars have the characteristics of equal length, equal distance and vertical arrangement direction; the method comprises the steps of obtaining an upper boundary and a lower boundary of a candidate reinforcing steel bar according to the intersection point of projection of rays and an upper offset plane and a lower offset plane, selecting a plurality of target reinforcing steel bars which need to be subjected to intersection test from the candidate reinforcing steel bars according to the upper boundary and the lower boundary, wherein the upper offset plane and the lower offset plane are two planes formed by offsetting the distance of a cylindrical radius r along a normal line up and down by an axis; and respectively carrying out intersection calculation on all target reinforcing steel bars to replace intersection calculation of the combined reinforcing steel bars.
7. An implicit expression and rendering device of a rebar model, comprising: The parameter calculation module is used for acquiring and analyzing the IFC file of the steel bar model to obtain a space coordinate system level corresponding to the steel bar model, and sequentially superposing relative coordinates among the levels according to the combination information to obtain the global coordinates of each single steel bar in the steel bar model; The implicit expression module is used for setting an object space coordinate system of the cube grid as a coordinate system of implicit expression of the steel bar model, under the coordinate system, expressing the global coordinates of the single steel bar as the space coordinates of two endpoints of a cylinder, and constructing a corresponding implicit expression equation in the space of the cube grid according to classification and combination information of the steel bar model, wherein the single steel bar in the steel bar model takes the two endpoints of the cylinder as vectors, and the radius of the cylinder The method comprises the steps of taking a combined steel bar as a scalar, carrying out implicit expression by combining combined information on the basis of a single steel bar, wherein the radius parameter of the implicit expression corresponds to 1/2 of the diameter of the steel bar in the steel bar model, and the sweep path parameter corresponds to the axis track of the steel bar; a rendering module for defining a ray equation as Combining the sweep path and the ray equation of the single steel bar, executing intersection test of rays and the single steel bar in a colorant, traversing all the single steel bars in the steel bar model in sequence, judging whether an implicit graphic element is hit or not according to the intersection test result of the single steel bar, mixing a plurality of judgment results to obtain a visual result of implicit expression of the steel bar model, As a starting point for the ray, As the direction in which the radiation is advanced, Is a parameter of the ray.
8. A storage medium having stored thereon a computer program which, when executed by a processor, implements the implicit expression and rendering method of a rebar model as claimed in any one of claims 1 to 6.

Description

Implicit expression and rendering method and device of reinforcement model and storage medium Technical Field The invention belongs to the field of BIM, and particularly relates to an implicit expression and rendering method and device of a reinforcement model and a storage medium. Background In the BIM native visualization process, a tessellation pipeline is typically utilized to generate a triangular mesh of parametric models, e.g., the open source BIM framework xBIM provides GetGeometryData methods to obtain the geometric information of the components in the BIM. For the rebar model, more triangles are generated in the process to fit the cylindrical curved surface property of the rebar model. Common approaches include reducing the level of tessellation and using LOD methods to achieve the goal of reducing the number of triangles in a scene. Explicit representation of the rebar model in a triangular mesh requires as few triangles in the scene as possible to enable rendering to achieve a certain frame rate. In the prior art, the method for controlling the subdivision level of the curved surface can effectively reduce the number of triangles in a scene, but the cost is that the accuracy of the visualization is seriously reduced, and the balance of the accuracy and the efficiency is a very difficult choice. The LOD method introduces several models with high precision and low precision, which further aggravates the memory overhead of rendering the scene and requires the developer to manually adjust the appropriate model switching strategy. For example, when the number of the steel bars reaches 10 ten thousand, the number of triangles generated by the existing curved surface subdivision method is about 1000 ten thousand, the video memory occupies more than 4GB, the rendering frame rate is lower than 30fps, 3-5 different precision models are required to be additionally stored by adopting the LOD method, the video memory overhead is increased by 40%, and visual faults are easy to occur when the models are switched. In the prior art, implicit expression is mostly used for free-form surface modeling (such as an automobile shell), but is never applied to BIM (building information modeling) steel bar models, and because the steel bar models have the characteristics of large quantity, regular arrangement and linkage with BIM parameters, the direct application of conventional implicit functions can lead to incompatible parameters and low intersection efficiency. Disclosure of Invention Aiming at the defects of the related art, the invention aims to provide a method, a device and a storage medium for implicit expression and rendering of a reinforcement model, which aim to solve the problem of suitability of the implicit expression in BIM reinforcement scenes. In order to achieve the above object, in a first aspect, the present invention provides a method for implicit expression and rendering of a rebar model, including: Acquiring and analyzing an IFC file of a reinforcing bar model to obtain a space coordinate system level corresponding to the reinforcing bar model, and sequentially superposing relative coordinates among the levels according to the combination information to obtain global coordinates of each single reinforcing bar in the reinforcing bar model; Setting the object space coordinate system of the cube grid as the coordinate system of the implicit expression of the steel bar model, under the coordinate system, expressing the global coordinates of the single steel bar as the space coordinates of two end points of a cylinder, and constructing a corresponding implicit expression equation in the space of the cube grid according to the classification and combination information of the steel bar model, wherein the single steel bar in the steel bar model takes the two end points of the cylinder as vectors, and the radius of the cylinder The method comprises the steps of taking a combined steel bar as a scalar, carrying out implicit expression by combining combined information on the basis of a single steel bar, wherein the radius parameter of the implicit expression corresponds to 1/2 of the diameter of the steel bar in the steel bar model, and the sweep path parameter corresponds to the axis track of the steel bar; Defining the ray equation as Combining the sweep path and the ray equation of the single steel bar, executing intersection test of rays and the single steel bar in a colorant, traversing all the single steel bars in the steel bar model in sequence, judging whether an implicit graphic element is hit or not according to the intersection test result of the single steel bar, mixing a plurality of judgment results to obtain a visual result of implicit expression of the steel bar model,As a starting point for the ray,As the direction in which the radiation is advanced,Is a parameter of the ray. Optionally, the space coordinate system is hierarchical, and hierarchical division is performed sequentially by a b