glTF-BinExport

aske · April 9, 2021, 11:47am

This plugin can export Rhino objects to glTF (.gltf and .glb) for use on the web/mobile/VR/etc.

Example

Rhino

Exported Result Viewed in browser

Install

Use the PackageManager with pre-release checked, and search for glTF-BinExporter.

Usage

File Export plugin. Just select glb or gltf.
Also exposes a single command glTFBinExport that exports the selected objects to a .gltf and .glb.

For how to use the resulting glb file see e.g. ThreeJS GLTFLoader Example
NOTE: The DracoCompression extension is required, if exporting with DracoCompression.

Geometry

Geometry can optionally be compressed with DracoCompression.

Materials

Physcially based MetalRoughness materials are copied into the resulting .glb. Normal materials are converted in a best-effort way.

Textures

Textures from the material are included into the exported file.

Known Limitations

Lights.
Cameras.
Animations.

Releases

We’ll keep posting here with updates for new releases, so subscribe to this topic.

Latest release:

For Developers

The code is open source and can be found here https://github.com/Stykka/glTF-Bin

wim · December 14, 2020, 3:04pm

Hi Aske -

That one is failing here on Windows. There’s no RHP file in that RHI:

-wim

stevebaer · December 14, 2020, 3:54pm

Since you are building for V7, I would highly recommend dropping the rhi/macrhi distribution method and go with the package manager. It is a much better way to distribute.

aske · December 17, 2020, 4:16pm

Thanks, I’ll try that instead!

aske · December 17, 2020, 6:43pm

I’m shocked at how easy the package manager was to use! Awesome work to whoever at McNeel did that!

I’ve published it as a pre-release under the name glTF-BinExporter and tested that the basic functionality is there on both Mac and Windows.

ryan.rhino.odom · December 18, 2020, 9:34am

Getting closer!

I know you already noted cubes and spheres don’t work but I am getting textures to come through. Rad!

One thing I noticed is that I cannot select meshes to export and thus have no control it’s density and resolution.

aske · December 18, 2020, 9:52am

Cool you tried it out and got something working!

Honestly didn’t try meshes yet. My hacky approach was just to steal the render mesh and export that for Breps. Meshes should be easy to add though. I think I might have some free time over the weekend!

nathanletwory · December 18, 2020, 11:33am

@aske I have not been able yet to import any of the glb files created by your plug-in into Blender 2.91. For the two exports I tried the add-on tells me that parsing failed.

The import/export add-on in Blender is maintained here: https://github.com/KhronosGroup/glTF-Blender-IO

aske · December 18, 2020, 12:28pm

Hi @nathanletwory

Thanks for reporting!
I only export DracoCompressed geo for now (didn’t have bandwidth to fix two different codepaths) Is it possible that Blender is just not able to import that? It’s only listed under export as far as I can tell.

nathanletwory · December 18, 2020, 12:29pm

That could very well be I guess. I didn’t dig into the issue tracker on Github to figure that out.

aske · December 20, 2020, 6:07pm

I published a new version that supports Meshes. Instead of using the RenderMesh like other geometry, it should take your mesh directly and pipe it through DracoCompression.

In your example I see the UV map is incorrectly exported. How is it mapped? I tried a sphere that got correctly exported with the latest version at least.

ryan.rhino.odom · December 21, 2020, 5:37am

Thanks! meshes work.

I was using surface mapping when I got the result above. I change it to spherical mapping and the texture works better. I’m getting pinching at the top in Google Model Viewer that I don’t see in Rhino. What would need to happen for Bump Maps to export to GLB?

aske · December 21, 2020, 1:15pm

I was using surface mapping when I got the result above. I change it to spherical mapping and the texture works better.

Never looked at UV mapping in Rhino, so I would need to dive into that to solve it. Maybe need to bake a UV map on the fly. I think I would down prioritize this: users could work around it, by converting it to Mesh with an explicit plain old UV map. Do you think that would be acceptable?

What would need to happen for Bump Maps to export to GLB?

I need to figure out what types of bump/normal/parallax/other maps Rhino supports, and how they map to GLB (I think GLB just uses Normal maps?). Shouldn’t be too hard though. Bump -> normal is easy, normal -> normal as well.

aske · December 21, 2020, 9:57pm

Added normal maps now.

ryan.rhino.odom · December 21, 2020, 11:58pm

Thanks for devoting some time to this so fast. I’m getting some unexpected results when exporting with normal maps.

nathanletwory · December 22, 2020, 12:07am

You’ll get similar pinching if you use ExtractRenderMesh and then show that instead of the sphere surface with spherical mapping. The Rendered mode is able to do per-pixel mapping, whereas with the mesh with (essentially baked) UV coordinates you can’t. Higher density mesh will yield nicer results, but there’ll always be some pinching - at the cost of increased memory usage.

aske · January 3, 2021, 6:48pm

I’ve just released the source code for anyone who wants to take a look: https://github.com/Stykka/glTF-Bin

aske · January 8, 2021, 10:48am

Pushed an update thanks to @Joshua_Kennedy. He fixed these issues:

Color alpha out of bounds.
Texture filter constants set to valid values.

aske · February 14, 2021, 2:07pm

New release 1.5.0.0, also courtesy of @Joshua_Kennedy

Add the ability to export geometry without DracoCompression.
Fixes crash when getting material if none has been assigned.
Bumped deps.

edit:
Forgot to add:

The plugin is now a file utlity plugin, making it possible to export from the File menu by selecting gltf/glb in the file type.

aske · February 14, 2021, 2:06pm

@Joshua_Kennedy has been at it again! This time mostly internals changed to make everything more robust by switching from my hand-written brittle gltf solution, to using a generator based on the schema directly from KhronosGroup (creators of the gltf spec). This means some validation errors that were present before are now gone, improving portability of the resulting files.
Released as 1.6.0.0.
Please let me know if you encounter any errors.