Exporter Ecosystem Matrix and Checklist

[robertlong]

Currently we have a number of glTF exporters with partial support for glTF 2.0. It would be great if we could help artists find the right exporter for their pipeline and required features. We'd also like to help developers find the best projects for them to contribute to.

I'm compiling a matrix of exporters and their supported features. I could use the help of the community in building this matrix. I've created an exporter feature checklist for people to fill out and submit in this thread. I'll add it to the matrix and we can update it as these exporters mature. Hopefully, this pushes people to fill in the missing pieces of these exporters and we can enjoy a more robust exporter ecosystem.

Please let me know if there are items that should be added, removed, or changed in this list. My intention is to keep it high level enough that it isn't information overload, but detailed enough that you can find out if the exporter will work for you. Thank you!

glTF Exporters

Exporter Name	.gltf/.bin	.glb	Morph Targets	Skinned Mesh	Buffer View and Accessor Reuse	Mesh Instancing	PBR Metallic Roughness	PBR Specular Glossiness (Extension)	Unlit Material (Extension)	Additional Maps	Multiple UV Sets	Alpha	Double Sided Materials	Cameras	Animation (TRS)	Animation (Weights)	Animation (Multiple)	Draco Mesh Compression (extension)	Extras Data	Asset Info
glTF-Blender-Exporter	✔️	✔️	✔️	✔️	❔	❔	✔️	✔️	✔️	✔️	❔	✔️	⚠️	✔️	✔️	✔️	❌	❌	✔️	✔️
FBX2glTF	✔️	✔️	✔️	✔️	❔	❔	✔️	❌	✔️	✔️	❔	✔️	❌	✔️	✔️	✔️	❌	✔️️	❌	⚠️
blendergltf	✔️	✔️	✔️	✔️	❔	❔	✔️	❌	✔️	✔️	❔	✔️	✔️	✔️	✔️	✔️	✔️	❌	✔️	✔️
obj2gltf	✔️	✔️	❌	❌	❔	❔	⚠️	⚠️	❌	✔️	❔	✔️	❌	❌	❌	❌	❌	❌	❌	❌
Babylon.js 3dsMax gltf exporter	✔️	✔️	✔️	✔️	❔	❔	✔️	❌	❌	✔️	❔	❌	✔️	✔️	✔️	✔️	✔️	❌	❌	✔️
Babylon.js Maya gltf exporter	✔️	✔️	✔️	✔️	❔	❔	✔️	❌	❌	✔️	❔	❌	❌	✔️	✔️	✔️	✔️	❌	❌	✔️
Maya2glTF	✔️	✔️	✔️	✔️	❔	❔	✔️	❌	❌	✔️	❔	✔️	❌	❌	✔️	✔️	✔️	❌	❌	✔️
UnityGLTF	⚠️	❌	❌	❌	❔	❔	✔️	✔️	❌	✔️	❔	✔️	❌	❌	❌	❌	❌	❌	❌	⚠️
Sketchup glTF Export	⚠️	✔️	❌	❌	❔	❔	❌	❌	❌	❌	❔	✔️	✔️	❌	❌	❌	❌	❌	❌	⚠️
COLLADA2GLTF	✔️	✔️	❌	✔️	❔	❔	⚠️	⚠️	✔️	❌	❔	❌	✔️	✔️	✔️	❌	❌	✔️	❌	❌

Key:

• ✔️ Full support
• ⚠️ Partial Support
• ❌ No Support
• ❔ Needs Data

glTF Exporter Checklist

• JSON Export (.gltf, .bin, .png/.gif/.jpg)
  The exporter can output a .gltf file, a .bin file, and images for each of the textures.
• Binary Export (.glb)
  The exporter can output a single .glb file containing the glTF JSON data, buffer data, and textures.
• Morph Targets
  The exporter outputs morph target information via primitive.targets and primitive.weights. This does not include animation of the weights.
• Skinned Mesh
  The exporter outputs skins using the inverseBindMatrices, joints, and skeleton properties as well as the JOINTS and WEIGHTS vertex attributes.
• Buffer View and Accessor Reuse
  The exporter reuses buffer views and accessors whenever possible. Ex. Vertex attributes are packed into a single buffer view and meshes with the same geometry, but different materials reuse accessors.
• Mesh Instancing
  When multiple nodes have the same mesh, the exporter exports a single mesh definition and references it in each node.
• PBR Metallic Roughness Material
  The exporter outputs the correct factors and textures for the pbrMetallicRoughness material.
• KHR_matrials_pbrSpecularGlossiness
  The exporter outputs the correct factors and textures for the pbrSpecularGlossiness material.
• KHR_material_unlit
  The exporter supports exporting unlit materials. The material has the correct fallback values.
• Additional Maps
  The exporter outputs the correct factors and textures for the normal, occulsion, and emissive maps.
• Multiple UV Sets
  The exporter can output materials which use multiple UV sets.
• Alpha Coverage
  The exporter outputs the correct alphaMode, alphaCutoff and alpha value for the given material.
• Double Sided Material
  The exporter can specify whether or not the material is double sided and outputs the correct doubleSided value.
• Cameras
  The exporter supports exporting both perspective and orthographic cameras.
• Animation (TRS)
  The exporter supports exporting animations of the translation, rotation, and scale properties of nodes. This includes joints in skinned meshes.
• Animation (Weights)
  The exporter supports exporting animation of morph target weights.
• Animation (Multiple)
  The exporter supports exporting multiple animations.
• KHR_draco_mesh_compression
  The exporter supports exporting compressed meshes via the Draco mesh compression library.
• Extras Data
  The exporter allows you to specify extras data on (at minimum) node objects for adding application specific metadata.
• Asset Information
  The exporter outputs the correct glTF version, the generator name, and allows you to specify the copyright field.

Post template

# Exporter Name
- [ ] JSON Export (.gltf, .bin, .png/.gif/.jpg)
- [ ] Binary Export (.glb)
- [ ] Morph Targets
- [ ] Skinned Mesh
- [ ] Buffer View and Accessor Reuse
- [ ] Mesh Instancing
- [ ] PBR Metallic Roughness Material
- [ ] KHR_matrials_pbrSpecularGlossiness
- [ ] KHR_material_unlit
- [ ] Additional Maps
- [ ] Multiple UV Sets
- [ ] Alpha Coverage
- [ ] Double Sided Material
- [ ] Cameras
- [ ] Animation (TRS)
- [ ] Animation (Weights)
- [ ] Animation (Multiple)
- [ ] KHR_draco_mesh_compression.
- [ ] Extras Data
- [ ] Asset Information

If a feature is missing, please try to provide some details. If it has partial or no support please indicate that. Linking to specific Github issues would be even better!

[donmccurdy]

That is a beautiful and ambitious matrix you have created. 😁

Could I request an extra column for multiple animations? Sadly it is painfully missing from nearly all of these. I might also vote to remove the Draco column, as it feels like something that could be more effectively implemented as a post-optimization rather than in each exporter.

[donmccurdy]

glTF-Blender-IO

• ✔️ JSON Export (.gltf, .bin, .png/.gif/.jpg)
• ✔️ Binary Export (.glb)
• ✔️ Morph Targets
  (generally works well, but a few issues)
• ✔️ Skinned Mesh
  (certain workflows, e.g. parenting to bones, must be avoided)
• ✔️ PBR Metallic Roughness Material
• ✔️ KHR_matrials_pbrSpecularGlossiness (requires custom Cycles node)
• ✔️ KHR_material_unlit
• ✔️ Additional Maps
• ✔️ Alpha Coverage
• ✔️ Double Sided Material
• ✔️ Cameras
• ✔️ Animation (TRS)
• ✔️ Animation (Weights)
• ✔️ Animation (Multiple)
• ✔️ KHR_draco_mesh_compression (export only)
• ✔️ Extras Data
• ✔️ Asset Information

(NOTE: Maintainers please feel free to edit this comment if it needs correction, to keep the comment churn limited.)

[zellski]

From memory, this is FBX2glTF, but feel free to edit the borderline cases as you like:

FBX2glTF

• ✔️ JSON Export (.gltf, .bin, .png/.gif/.jpg)
• ✔️ Binary Export (.glb)
• ✔️ Morph Targets
• ✔️ Skinned Mesh
• ✔️ PBR Metallic Roughness Material
• ❌ KHR_matrials_pbrSpecularGlossiness
  • (support recently removed, as there's no existing natural source of such materials in the FBX world that I know of)
• ✔️ KHR_material_unlit
• ✔️ Additional Maps
• ✔️ Alpha Coverage
  • (only blend/opaque -- not sure FBX materials have test?)
• ❌ Double Sided Material
  • (not sure FBX materials have this?)
• ✔️ Cameras
• ✔️ Animation (TRS)
• ✔️ Animation (Weights)
• ❌ Animation (Multiple)
• ✔️ KHR_draco_mesh_compression.
• ❌ Extras Data
  • (this seems tricky to do in a general way -- why node especially?)
• ⚠️ Asset Information
  • (option to set copyright is a great idea, will fix)

[Kupoman]

blendergltf

• ✔️ JSON Export (.gltf, .bin, .png/.gif/.jpg)
• ✔️ Binary Export (.glb)
• ✔️ Morph Targets
• ✔️ Skinned Mesh
• ✔️ PBR Metallic Roughness Material
• ❌ KHR_matrials_pbrSpecularGlossiness
• ✔️ KHR_material_unlit
• ✔️ Additional Maps
• ✔️ Alpha Coverage
• ✔️ Double Sided Material
• ✔️ Cameras
• ✔️ Animation (TRS)
• ✔️ Animation (Weights)
• ✔️ Animation (Multiple)
• ❌ KHR_draco_mesh_compression.
• ✔️ Extras Data
• ✔️ Asset Information

edit: Added support for KHR_materials_unlit and control of the doubleSided material option.
edit: Added "Animation (Multiple)"
edit: Update Alpha Coverage status to supported

[emackey]

@donmccurdy I updated the doubleSided one to say:

⚠️ Double Sided Material (requires custom Cycles node, doesn't use Blender's own flag)

[robertlong]

I updated the matrix, added the multiple animations column, and edited the comments.

@donmccurdy and @Kupoman could you fill in the multiple animations item in your checklists? I think it's missing from both of those exporters, but I could be wrong.

@zellski the extras data on node is useful for application specific behavior that doesn't belong in an extension. I think it's hard to do in a general way to all the glTF properties, but node seems like it would be the easiest and most useful.

@donmccurdy I'd rather keep the Draco column. I think it's useful to be able to export an optimized asset directly from an exporter. Not all of them will implement the extension and when they don't users can use the glTF pipeline tool or some Draco compression tool.

[donmccurdy]

@donmccurdy and @Kupoman could you fill in the multiple animations item in your checklists?

I've updated both — blendergltf supports multiple animations, and support is in progress for the Khronos exporter.

@donmccurdy I'd rather keep the Draco column.

Ok, sounds good.

[donmccurdy]

obj2gltf

• ✔️ JSON Export (.gltf, .bin, .png/.gif/.jpg)
• ✔️ Binary Export (.glb)
• ❌ Morph Targets
• ❌ Skinned Mesh
• ⚠️ PBR Metallic Roughness Material
  OBJ does not have PBR materials, approximate conversion available.
• ⚠️ KHR_matrials_pbrSpecularGlossiness
  OBJ does not have PBR materials, approximate conversion available.
• ❌ KHR_material_unlit
• ✔️ Additional Maps
• ✔️ Alpha Coverage
• ❌ Double Sided Material
• ❌ Cameras
• ❌ Animation (TRS)
• ❌ Animation (Weights)
• ❌ Animation (Multiple)
• ❌ KHR_draco_mesh_compression.
• ❌ Extras Data
• ❌ Asset Information

[pjcozzi]

Any chance the following folks could chime in on their glTF exporter capabilities?

• @lasalvavida - COLLADA2GLTF
• @ziriax - Maya2glTF
• @deltakosh - BabylonJS Max glTF exporter
• @bghgary - UnityGlTF
• @pissang - Clay fbx2gltf
• @albn - Sketchfab
• @kimkulling - assimp

Thanks, it is deeply appreciated! 👏

[deltakosh]

Sure thing!

[deltakosh]

Babylon.js 3dsMax gltf exporter

• JSON Export (.gltf, .bin, .png/.gif/.jpg)
• Binary Export (.glb)
• Morph Targets
• Skinned Mesh
• PBR Metallic Roughness Material
• KHR_matrials_pbrSpecularGlossiness
• KHR_material_unlit
• Additional Maps
• Alpha Coverage
• Double Sided Material
• Cameras
• Animation (TRS)
• Animation (Weights)
• Animation (Multiple)
• KHR_draco_mesh_compression.
• Extras Data
• Asset Information

[deltakosh]

Babylon.js Maya gltf exporter

• JSON Export (.gltf, .bin, .png/.gif/.jpg)
• Binary Export (.glb)
• Morph Targets
• Skinned Mesh
• PBR Metallic Roughness Material
• KHR_matrials_pbrSpecularGlossiness
• KHR_material_unlit
• Additional Maps
• Alpha Coverage
• Double Sided Material
• Cameras
• Animation (TRS)
• Animation (Weights)
• Animation (Multiple)
• KHR_draco_mesh_compression.
• Extras Data
• Asset Information

[pjcozzi]

Very nice, thank you kindly @deltakosh!

[ziriax]

Maya2glTF exporter

• JSON Export (.gltf, .bin, .png/.gif/.jpg)
• Binary Export (.glb)
• Morph Targets
• Skinned Mesh
• PBR Metallic Roughness Material
• KHR_matrials_pbrSpecularGlossiness
• KHR_material_unlit
• Additional Maps
• Alpha Coverage
• Double Sided Material
• Cameras
• Animation (TRS)
• Animation (Weights)
• Animation (Multiple)
• KHR_draco_mesh_compression.
• Extras Data
• Asset Information

Details

• Fully supports and exports Khronos PBR shader, ported to Maya GLSL material
• Merges metallic, roughness, occlusion into a single texture
• Handles mirrored UVs (bitangent sign)
• Supports alphaMode only, no cutoff yet
• Always bakes animation so all Maya constraints and modifiers can be used
• Reconstructs different hierarchy based on selection
• Can use a MikkTspace for generating tangents
• Converts standard Maya materials to PBR (partially)
• Supports 16- and 32-bit indices
• Blend shapes are reconstructed by sampling the output meshes, allowing subdivision modifiers and complex graphs
• Allows specification of attributes that should be exported

Short term backlog (coming weeks)

• adding extra glTF nodes to support Maya’s segment scale compensation
• support for Trax clips
• MEL user interface

Long term:

• support for shearing by introducing extra nodes and using SVD
• qtangents (requires extension)
• exporting scaling and quaternions in log domain (requires extension)
• dual quaternions/projective_geometric_algebra skinning
• custom Maya blend shape modifier to blend custom normals
• DirectX shader
• unit and regression tests
• continuous integration

Desired pull requests

• porting to MacOS and Linux, using CMake
• support for Draco compression