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warrenm / GLTFKit2

A glTF 2.0 asset loader and exporter for Objective-C and Swift.
MIT License
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Feature Request: Add GLB Export Functionality #64

Open thomas-graphopti opened 1 week ago

thomas-graphopti commented 1 week ago

Hello,

Could you please consider adding a .glb export function to GLTFKit2? This feature would enhance versatility, especially since USD/USDZ lacks broader support. Thanks for all your work on this valuable tool!

warrenm commented 1 week ago

This is a reasonable request.

Technically, export is already implemented on the feature/export branch, and it does allow round-tripping of static assets from .gltf/.glb files to GLTFAsset and back.

But creating a GLTFAsset from a scene that didn't begin life as a glTF asset is another story; you'd need to manually create all of the model objects, images, buffers, etc. first, and then use the export machinery. The reason we've been slow to implement export is that it's not guaranteed that we'll have feature parity with any of the common places you'd want to export from (i.e. SceneKit and RealityKit).

For that reason, it would be helpful to know more about your use cases. What kinds of scenes are you exporting, and what form do you want to export them from? It's not a goal of this project to be a generic format converter (that's why things like usd2gltf exist), but I'm open to trying to support limited use cases as long as the expectation is set that we're simply not going to attain 1:1 feature parity with arbitrary RealityKit scenes or whatever.

thomas-graphopti commented 1 week ago

hi @warrenm.

Thank you for your response and for the work you’re doing on this valuable tool!

I’m currently developing a 3D asset manager for iOS. While Apple’s ModelIO and SceneKit support exporting textured 3D assets in formats like OBJ and USDZ, I would prefer to save assets in the .glb format due to its high compression and reduced file size.

After researching available solutions, I’ve found that there aren’t many options on iOS for this specific need. Having .glb export functionality in GLTFKit2 would be incredibly helpful and greatly enhance the tool’s versatility.

Thank you again for considering this feature, and I appreciate all the thought you’ve put into making GLTFKit2 as powerful as it is!