Before introducing BIM lightweight, we must first understand what BIM is. Simply put, BIM is a three-dimensional model containing construction engineering information, and the data mainly includes two aspects: geometric information, professional attributes and state information of components; Non-component state information (such as space and motion behavior).
It can be seen that the BIM model involves huge data and files, and the traditional BIM application is based on desktop client, which requires high computer configuration. With the development of the Internet, more and more users want to browse 3D models through their mobile phones or by logging into browsers. Therefore, in order to make better use of BIM model, the demand for lightweight BIM arises at the historic moment.
The lightweight of BIM model aims to reduce the size of BIM model as much as possible and make it more suitable for web and mobile terminals. In this process, BIM model actually went through two stages: geometric transformation and rendering.
Geometric information mainly refers to two-dimensional and three-dimensional models that can be seen in daily life. By describing the geometric information of a single component in a parametric way, lightweight can be realized. In addition, the geometric optimization transformation of the model can be carried out with the help of triangular patches and similarity algorithms to reduce the number of primitives.
In the process of drawing, octree can be used to quickly eliminate invisible primitives and reduce the number of drawing objects entering the drawing area. This technology has been very mature in the desktop 3D display engine. In addition, you can use multiple LODs (Levels of Detail) to speed up the rendering of a single entity.
Geometric transformation and rendering is the core technology of lightweight BIM model, which has certain technical threshold and requires developers to master certain graphics technology. Therefore, various BIM lightweight engines are constantly emerging in the market. Such as guanglianda BIMFACE, Glendale webglBIM lightweight engine, autodesk forge, modelo and so on.
As above, I hope to help the landlord, thank you ~ ~