I'm an experienced SceneKit developer and I want to begin work on a new project using RealityKit. So I appreciated as timely, the WWDC 2025 Session, "Bring your SceneKit project to RealityKit".
However, now I am finding that:
Blender does not properly support exporting armatures in usdc files, and usdc is really the only file format that should be used for creating 3D assets for RealityKit.
The option of exporting from Blender to fbx or some other intermediate format, and then converting that to usdc, is a challenge.
Apple's Reality Converter App, which supposedly can support importing and converting fbx files to usdc, is no longer available from Apple's website. And an older copy of it I found at the Kodeco website requires Rosetta on Apple Silicon. As well, this older copy does not in fact import fbx or anything else - I find it doesn't work at all.
Apple's Reality Composer Pro, at least as far as I can tell, only supports importing usdc - it is not a file conversion tool.
Alternatively, I am under the impression that Maya supports producing usdc files with armatures, but Maya costs over $2000 per year and I am skilled with Blender, so I believe strongly that I should be able to continue with Blender. Maya's expense and skillset simply shouldn't be a requirement for building RealityKit applications.
What are my options then, if any, to produce assets with armatures and armature based animations using Blender, and then bring them into RealityKit?
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Hello,
I've been trying to leverage instanced rendering in RealityKit on visionOS but have not had success.
RealityKit states this is supported:
https://developer.apple.com/documentation/realitykit/validating-usd-files
https://developer.apple.com/videos/play/wwdc2021/10075/?time=1373
https://developer.apple.com/videos/play/wwdc2023/10099/?time=772
RealityKit Trace metrics
Validating instancing is working:
To test I made a base visionOS app with immersive space and the entity replaced with my test usdz file. I've been using the RealityKit Trace profiling template in xcode instruments in the immersive space and volume closed. This gets consistent draw call results.
If I have a single sphere mesh with one material I get one draw call, but the number of draw calls grows linearly with mesh count no matter how my entity is configured.
What I've tried
Create a test scene in blender, export with instancing enabled
Create a test scene in Reality Composer Pro using references
Author usda files by hand based on the OpenUSD spec
Programatically create a MeshResource with Contents at runtime
References
https://openusd.org/release/api/_usd__page__scenegraph_instancing.html
https://developer.apple.com/documentation/realitykit/meshresource
https://developer.apple.com/documentation/realitykit/meshresource/instance
Thank you