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How to conduct a simple analysis of open source objTo3d-tiles, many novices are not very clear about this, in order to help you solve this problem, the following editor will explain for you in detail, people with this need can come to learn, I hope you can gain something.

ObjTo3d-tiles tool.

I took a look at the contents of the tool, then looked at the source code, tested it according to the sample data, and loaded the data into cesium for viewing. Simply analyze the code and functions. 3dtiles model format is b3dm/i3dm, etc., the code is the need to convert the obj format of the model into the above format, gltf is an important part of b3dm/i3dm, so, the tool is to convert obj into gltf/glb first, according to the description of Batched3DModel, add the corresponding BatchTable and FeatureTable information on the gltf/glb, combined into b3dm/i3dm files. With the b3dm/i3dm file, we also need to add the file coordinate information and transformation information of the model to tileset.json. Among them, the boundingVolume of the model is divided into three forms: region, box and sphere, which needs to be calculated in Cesium according to the actual size of the model. The key implementation code: createGltf.js, createB3dm.js, createSingleTileset.js, getBufferPadded8Byte.js, getJsonBufferPadded8Byte.jstileset.json set the conversion information of transform, because the coordinate system of the model is generally YUP, so, to the three-dimensional scene, need a coordinate transformation, in some tools generated by 3dtiles, usually integrate this transformation into the b3dm/i3dm file. Multiple model files need to be merged with tileset.json, which is implemented in combineTileset.js. When obj is converted to gltf/glb, there is sometimes a conversion problem. You can use other tools to convert it to gltf/glb in advance, and then modify the code for integration generation.

In this way, the 3dtiles combines multiple 3D models, and there are still some problems in performance, and the lod and data index of the model need to be trimmed to optimize the performance. Is it helpful for you to read the above content? If you want to know more about the relevant knowledge or read more related articles, please follow the industry information channel, thank you for your support.

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