Open Access

ARTICLE

3D Model Occlusion Culling Optimization Method Based on WebGPU Computing Pipeline

Liming Ye^1,2, Gang Liu^1,2,3,4,*, Genshen Chen^1,2, Kang Li^1,2, Qiyu Chen^1,2,3, Wenyao Fan^1,2, Junjie Zhang^1,2

1 School of Computer Science, China University of Geosciences, Wuhan, 430074, China
2 Hubei Key Laboratory of Intelligent Geo-Information Processing, China University of Geosciences, Wuhan, 430074, China
3 State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, China
4 Key Laboratory of Resource Quantitative Assessment and Geoscience Information, Ministry of Natural Resources, Wuhan, 430074, China

* Corresponding Author: Gang Liu. Email:

Computer Systems Science and Engineering 2023, 47(2), 2529-2545. https://doi.org/10.32604/csse.2023.041488

Received 24 April 2023; Accepted 01 June 2023; Issue published 28 July 2023

Abstract

Nowadays, Web browsers have become an important carrier of 3D model visualization because of their convenience and portability. During the process of large-scale 3D model visualization based on Web scenes with the problems of slow rendering speed and low FPS (Frames Per Second), occlusion culling, as an important method for rendering optimization, can remove most of the occluded objects and improve rendering efficiency. The traditional occlusion culling algorithm (TOCA) is calculated by traversing all objects in the scene, which involves a large amount of repeated calculation and time consumption. To advance the rendering process and enhance rendering efficiency, this paper proposes an occlusion culling with three different optimization methods based on the WebGPU Computing Pipeline. Firstly, for the problem of large amounts of repeated calculation processes in TOCA, these units are moved from the CPU to the GPU for parallel computing, thereby accelerating the calculation of the Potential Visible Sets (PVS); Then, for the huge overhead of creating pipeline caused by too many 3D models in a certain scene, the Breaking Occlusion Culling Algorithm (BOCA) is introduced, which removes some nodes according to building a Hierarchical Bounding Volume (BVH) scene tree to reduce the overhead of creating pipelines; After that, the structure of the scene tree is transmitted to the GPU in the order of depth-first traversal and finally, the PVS is obtained by parallel computing. In the experiments, 3D geological models with five different scales from 1:5,000 to 1:500,000 are used for testing. The results show that the proposed methods can reduce the time overhead of repeated calculation caused by the computing pipeline creation and scene tree recursive traversal in the occlusion culling algorithm effectively, with 97% rendering efficiency improvement compared with BOCA, thereby accelerating the rendering process on Web browsers.

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Keywords

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