Research On Optimizing Lightweight Rendering Of BIM Large Model Based On Web

With the concept of Internet +,more and more industries join the Internet,and the construction industry is no exception.The digitization of building information has been developed for many years.Placing these digitized building information on the Internet is convenient for people to browse and use anytime,anywhere.However,as the amount of building information data soared,the difficulty of displaying rendering models also increased.How to lightweight these data and render them smoothly becomes an important issue.The research of web-based BIM large model lightweight rendering optimization research is mainly divided into two parts: research on model data lightweight research and web-based rendering optimization research.For the lightweighting of model data,an edge folding algorithm based on spatial screen error is proposed to generate LOD and LOD is used.The secondary error is used to control the simplified effect of LOD.The screen space error is used to control the timing of LOD switching and the effect of the entire rendering.Through experiments of model LOD generation and switching timing,it can be verified that the edge folding algorithm based on spatial screen error can well control LOD generation and switching.For web-based rendering optimization,an octree-based frustum culling algorithm,thread separation technology,and distance-based priority rendering algorithm are combined to achieve optimization.The octree-based frustum culling algorithm reduces entry rendering The amount of data in the pipeline;the thread separation guarantees rendering efficiency by separating calculation,storage,and rendering;the distance-based priority rendering algorithm implements the loading of near-to-far models and guarantees data by preferentially rendering components close to the viewpoint.The amount is below the browser memory threshold.In the experiment of rendering 500,000 cubes,the rendered frame rate was maintained above 50.This experiment proves that the front-end rendering method can support the rendering of large models.Finally,by lightweighting and rendering specific BIM large models,the model’s lightweighting and rendering effects are verified.The experimental results show that the engine that supports the weight reduction of BIM large models can easily lighten and render models with a data volume of more than 1G,maintain a rendering frame rate of more than 40,and obtain component information within 2s.