tinygltf/examples/mesh-conv

Mesh modify experiment

Sometimes we want to tweak mesh attributes(e.g. vertex position, uv coord, etc). glTF itself does not allow ASCII representation of such data so we need to write a converter.

This example show how to

• Export mesh data from .bin to .obj
• Import mesh data to .bin(update corresponding buffer data) from .obj

Features

• Support skin weights(JOINTS_N, WEIGHTS_N)

Supported attributes

• POSITION
• NORMAL
• TANGENT
• COLOR (vertex color)
• TEXCOORD_N
  • Only single texcoord(uv set) is supported
  • Specify --uvset 1 to specify which UV to use.
• WEIGHTS_N, JOINTS_N

Usage

Wavefront .obj to glTF

$ mesh-modify --op=obj2gltf input.obj

All shapes in .obj are concatenated and create single glTF mesh. (tinyobjloader's skin weight extension vw supported)

Limitation

Buffer is stored as external file(.bin)

glTF to Wavefront .obj

$ mesh-modify --op=gltf2obj input.gltf

.obj will be created for each glTF Mesh. (Skin weight data is exported to .obj using tinyobjloader's skin weight extension vw)

Limitation

Buffer is stored as external file(.bin)

TODO

• obj2gltf: Assign glTF material from .mtl
• modify/patch mesh geometry in glTF
  • By using JSON Patch or JSON Merge feature