Abstract: The rendering problem of BIM model in the web front end is an important problem in the practical application of BIM Technology. The solution to this problem is to use triangular patches to accelerate the rendering efficiency of the model front end (model lightweight). According to the problem that the average quality coefficient of triangle mesh of BIM model is low in the secondary development technology of Revit, aiming at the application requirements of BIM model lightweight and web-based sharing, an improved algorithm combining the secondary development of Revit and Delaunay subdivision algorithm is proposed. By adding points to the original points of BIM model obtained from the secondary development of Revit, the original points and the added points conform to the Delaunay criterion according to the B-W algorithm, and more precise triangular patches are generated. At the same time, the generation of extraterritorial triangles is avoided, and the practical application effect of the algorithm is improved. The experimental results show that the average mesh quality coefficient and mesh association quality coefficient of the improved algorithm are improved compared with the original algorithm. Finally, the BIM model is rendered by WebGL according to the triangle patch generated by the optimization algorithm, and the rendering of BIM model on the web side is realized, which verifies the effectiveness of the method.

Key words: BIM model, model lightweight, mesh quality, triangulation algorithm, WebGL render