Question

While looking into some webGL examples (mostly Three.js based examples) I noticed large models are loaded via a combination of ASCII+binary JSON. This approach is very attractive to me because of the reduced file size.
The ASCII JSON has the general format of (taken from Three.js example, webgl_geometry_large_mesh.html) :

{

    "metadata" :
    {
        "formatVersion" : 3,
        "sourceFile"    : "lucy100k.obj",
        "generatedBy"   : "OBJConverter",
        "vertices"      : 50002,
        "faces"         : 100000,
        "normals"       : 0,
        "uvs"           : 0,
        "materials"     : 0
    },

    "materials": [  {
    "DbgColor" : 15658734,
    "DbgIndex" : 0,
    "DbgName" : "default"
    }],

    "buffers": "Lucy100k_bin.bin"

}

As seen above, instead of a section containing a truck-load of vertices, normals, UVs, etc it is all packed into the referred binary file. Does anyone know how to create that binary file? Can I do it with Blender? If not, is there a script I can use?

Thanks

Answer 1

According to this line:

"generatedBy"   : "OBJConverter"

That file was generated by OBJConverter (from some .obj and .mtl files).

OBJConverter is a Python script called convert_obj_three.py sited in three.js / utils / converters / obj.

The own script has a comment about “How to get proper OBJ + MTL files with Blender”.