BIM模型轻量化技术研究与实现

Research and implementation of lightweight technology of BIM model

目前,国内对建筑信息模型(BIM)在项目中的应用需求越发迫切,数据冗杂的BIM大体量模型严重制约着BIM技术在实际应用中的使用。大体量BIM模型在展示过程中会遇到加载缓慢、显示卡顿的问题。为此,提出搭建BIM轻量化体系,通过自主研发的BIM仿真系统平台,为大体量BIM模型提供审阅浏览平台。采用几何简化算法、渲染优化算法、文件格式优化及数据结构设计4种方法对BIM轻量化体系进行搭建。对BIM模型三角面使用边折叠算法进行优化,根据多源异构数据的模型设计相应的文件格式和数据结构,在渲染层面上,自主研究并实现使用PagedLOD技术与几何简化模型结合、剔除与绘制双线程方法、批次绘制渲染优化技术,完成BIM轻量化体系的初步搭建工作并于平台中验证。实例验证效果显示:轻量化方法体系的应用使平台达到了快速加载大体量BIM模型并流畅展示的目标,拥有多源异构数据模型在同一平台展示的能力。

At present,the application of building information model(BIM)in projects is becoming more urgent in China,however the massive model of BIM with jumbled data seriously restricts the use of BIM technology in practical applications.Large BIM models have the problems of slow loading and stuck display in the display process.Therefore,it was proposed to build a BIM lightweight system,and provided a review and browsing platform for a large number of BIM models by self-developed BIM simulation system platform.Four methods were used to build BIM lightweight system,geometric simplification algorithm,rendering optimization algorithm,file format optimization and data structure design.The triangular surface of BIM model was optimized by edge folding algorithm.According to the model of multi-source heterogeneous data,the file format and data structure were designed.At the rendering level,the combination of PagedLOD technology and geometric simplified model,the double-thread method of rejection and rendering,and the rendering optimization technology of batch rendering were researched and implemented independently to complete the preliminary construction of BIM lightweight system and verified it in the platform.The results showed that the application of lightweight method system made the platform quickly load a large number of BIM models and smoothly display them,and had ability to display multi-source heterogeneous data models on the same platform.