glTF Export Phase 2

[atteneder]

glTF Export has landed in 4.4.0. Now it's time get it out of experimental

TODO

• [x] Run-time export via API

  • [x] Save to file
  • [x] Save to stream

• [x] Interfaces

  • [x] Editor context menu export of scene/objects

• [x] Documentation

• [ ] Optimize output for size

  • [x] node transform (skip default values)
  • [ ] Skip properties technically not required (like names)
  • [ ] (Option for) Minimized JSON
  • [ ] Precision rounding (e.g. 0.2 instead of 0.199999993)

• [x] Buffer layout

  • [x] Separate (non-interleaved; required for meshopt and 2019 LTS support)

• [ ] Materials

  • [ ] Shaders
  • [ ] BiRP Specular-Glossiness
  • [x] URP Lit
  • [x] URP Unlit
  • [x] HDRP Lit
  • [x] HDRP Unlit
  • [x] Textures
  • [x] Samplers
    • [x] fix redundant glTF textures
  • [x] Occlusion (ORM swizzle)
  • [x] Emissive
  • [x] MetallicRoughness (ORM swizzle)

• [ ] Tests

  • [ ] ~80% code coverage
  • [x] Validator Integration

• [ ] Skinning (weights and joints)

• [ ] Morph targets

• [ ] Animation

• [ ] Expose Export Settings

  • [ ] Texture compression (Auto/Always PNG)
  • [ ] Jpeg compression level
  • [x] Separate .gltf/.bin or Binary
  • [x] Active in hierarchy only

    Long-Term Features

• [ ] Async export

• [ ] Mesh quantization

• [ ] Sparse accessors

• [ ] GPU instancing

• [ ] Buffer layout

  • [ ] (Ideal) Unity layout

• [ ] Compression

  • [x] Draco mesh-level compression
  • [ ] meshopt bufferview-level compression
  • [ ] KTX2/BasisU texture compression

• [ ] Custom data in extras property

• [ ] XMP meta data

• [ ] Materials

  • [ ] TransmissionFactor/Texture
  • [x] Clear coat
  • [ ] Specular
  • [ ] Sheen
  • [ ] Volume
  • [ ] IOR
  • [ ] Specular/Glossiness workflow
  • [ ] Variants

• [x] Punctual lights

• [x] Camera

• [ ] DOTS export entity hierarchies

[ROBYER1]

Should I make an extra issue about GPU Instancing support? I want to use instanced meshes with an imported GLTF to save on file sizes.

[atteneder]

Should I make an extra issue about GPU Instancing support? I want to use instanced meshes with an imported GLTF to save on file sizes.

So you want the glTFast export to recognize Renderers with identical Meshes/Materials, so that it not only re-uses the Mesh, but adds a EXT_mesh_gpu_instancing extension, minimizing the instance overhead, right?

Yes, I'd suggest to make a dedicated issue, if it is of importance to you.

[ROBYER1]

Yes, I'd suggest to make a dedicated issue, if it is of importance to you.

I've set one up here https://github.com/atteneder/glTFast/issues/461