Research on LOD Lightweight Method of Railway Four Electric BIM Model

In view of the current BIM data volume, poor real-time rendering effect, and other problems. This paper proposes a research method to convert the BIM model of the four railways from RVT format to the 3DTiles data format and display it on the Web side with multiple LOD. The method is based on the secondary development of Revit to write a plug-in program, and realizes the application of the railway four-electrical model through lightweight model, model format conversion, and data dynamic scheduling. Firstly, the RVT model is converted to OBJ as an intermediate model through the secondary development of Revit. Then, the model is simplified to different degrees by the improved edge folding algorithm, to achieve the purpose of lightweight model. Finally, convert the simplified model to 3DTiles format, set the geometric error size, determine the LOD level, and introduce the Frustum Culling to achieve dynamic LOD display. Taking the model in railway engineering as an example, a high-speed railway station and components are selected for experimental analysis. The research results show that the proposed four-electric BIM model lightweight method can reduce the amount of model data as needed, and improve the real-time rendering efficiency and optimize the loading effect under the Cesium framework.