Can't play .glb animation with RealityKit

[HalTobin]

Hello,

I'm working on an app using RealityKit and .glb files. The models are loaded and displayed correctly, but their animations simply don't play.

I've tried the following:

• RealityKit + GLTFKit2 + .glb file (Not working)
• Filament + .glb file (Working)

Here's my current code:

public struct RealityKitRendererSimpleView: View {    
    let element: ArElement
    
    public init(element: ArElement) {
        self.element = element
    }
    
    public var body: some View {
        ZStack {
            RealityView { content in
                content.camera = .virtual
                
                let light = DirectionalLight()
                light.light.intensity = 2000
                light.position = [0, 3, 3]
                content.add(light)
                
                if let entity = await loadModel(element) {
                    for animation in entity.availableAnimations {
                        entity.playAnimation(
                            animation.repeat(duration: .infinity),
                            transitionDuration: 1.25,
                            startsPaused: false
                        )
                    }
                    
                    content.add(entity)
                }
            }
            .realityViewCameraControls(.orbit)
            .gesture(DragGesture(minimumDistance: 0).simultaneously(with: MagnificationGesture()))
            .background(Color.black.opacity(0.02))
        }
        .ignoresSafeArea(edges: .bottom)
    }
    
    private func loadModel(_ arElement: ArElement) async -> Entity? {
        let arModel = arElement.model
        let url = URL(fileURLWithPath: arElement.model.path)
        
        print("Loading: \(arElement.id)")
            
        switch url.pathExtension {
        case "usdz": do {
            print("USDZ Loader")
            do {
                let entity = try Entity.load(contentsOf: url)
                entity.name = String(arElement.id)
                
                let scaleFactor = arModel.scaleFactor?.floatValue ?? 0.5
                let yOffset = arModel.zOffset?.floatValue ?? 0.0
                entity.scale = .init(repeating: scaleFactor)
                entity.position = [0, yOffset, -1]
                
                return entity
            } catch {
                print("Couldn't load: \(arElement.id), error: \(error)")
            }
        }
        case "glb", "gltf": do {
            print("GLTF Loader")
            do {
                let entity = try await GLTFRealityKitLoader.load(from: url)
                entity.name = String(arElement.id)
                
                let scaleFactor = arModel.scaleFactor?.floatValue ?? 0.5
                let yOffset = arModel.zOffset?.floatValue ?? 0.0
                entity.scale = .init(repeating: scaleFactor)
                entity.position = [0, yOffset, -1]
                                
                return entity
            } catch {
                print("Couldn't load: \(arElement.id), error: \(error)")
            }
        }
        default:
            print("Unknown file format: \(url.pathExtension)")
        }
        
        return nil
    }
        
}

I've also attached a screenshot with the .glb loaded and a .zip containing the .glb file that I'm using.

tyrannosaurus.glb.zip

Thank you for reading this and have a great day!
Alexis

[warrenm]

Interesting. This works for me on top-of-tree and at the hash matching the 0.5.15 binary release, but it doesn't work when using the binary artifacts for release 0.5.15 via SPM. That seems to suggest that something went wrong with that binary release.

[warrenm]

Oh, that's embarrassing. I never pushed the Package.swift file with the updated URL and checksum for the 0.5.15 release . If you're using SPM, could you try re-resolving your package reference up to 0.5.15 and let me know if it works? Otherwise, if you're using a different configuration (downloaded xcframework, building from source, etc.) I'd love to hear more about that too.

[HalTobin]

Hello again,

I'm indeed using GLTFKit2 with SPM.
Unfortunately, I'm still not able to see any animations, I've tried the following steps:

• Resolve Package Versions
• Reset Package Caches
• Clean Build Folder
• Deleting DerivedData

I've made a simple repository that reproduce the error: https://github.com/HalTobin/RealityKitTest

[warrenm]

Thank you for your patience. The 0.5.15 release was associated with a tag/commit that didn't include the updated package file. I've now updated the tag to point to the correct commit, which should cause SPM to pick it up (though you may need to re-add the dependency and clear caches as before). You'll know it worked when the resolved Package.swift file points to a zip file with hash 9d0c338.

[HalTobin]

Indeed, I had trouble forcing Xcode to fetch the updated Package.swift file, but it's almost good now.
Most of the object is correctly animated, but not the eyes.