[QUESTION] Is there a more propper way to generate a mesh which contains primitives that have different vertex fragment types? about sharpgltf

[vpenades]

I'm afraid the only way to do what you want is to use the lower level APIs to construct the mesh on your own.

The way to do so is to create the vertex and index buffers, create the accessors, and then the mesh primitives and the mesh

[FlyingBamboo]

Thanks for your quick reply!
I can't give up on using the toolkit, so I'm going to try modifying the generated ModelRoot before saving to a glTF file.

[vpenades]

MeshBuilder uses a unique vertex definition for the whole mesh for two reasons:
1- it simplifies the mesh building process.
2- a single vertex format guarantees that all the vertex buffers used by the mesh can be merged into a single vertex buffer. Actually, if all the meshes of the model share the same vertex format, it could lead to use a single vertex buffer for the whole model.

Having said that, the post processor that converts the meshbuilder to a glTF mesh could be improved to identify attributes that have been filled with zeros, and re-arrange the data to remove unused attributes. The bad news is that this is one of the trickiest parts of the whole library and it would not be easy to deal with.