How to Make a Full Rotation Animation in ARView?

Question

I'm trying to make a model rotate a full rotation repeatedly forever using the following code:

func loadModel(named modelName: String) {
    if let modelEntity = try? Entity.loadModel(named: modelName) {
        modelEntity.generateCollisionShapes(recursive: true)
        modelEntity.transform.rotation = simd_quatf(angle: .pi/2, axis: [0, 1, 0])
        let anchorEntity = AnchorEntity(world: position)
        anchorEntity.addChild(modelEntity)
        installGestures(for: modelEntity)
        self.scene.addAnchor(anchorEntity)
        
        //***Animation***
        var transform = modelEntity.transform
        modelEntity.transform.rotation = simd_quatf(angle: -2 * .pi, axis: [0, 1, 0])
        let animationDefinition = FromToByAnimation(to: transform, duration: 3, bindTarget: .transform, repeatMode: .repeat)
        let animationViewDefinition = AnimationView(source: animationDefinition)
        let animationResource = try! AnimationResource.generate(with: animationViewDefinition)
        modelEntity.playAnimation(animationResource)

    }
}

However, the model rotates just around 90 degrees and restart repeatedly.

Question 1: How can I make the model make a full rotation (360 degrees) repeatedly instead?

Also, I found that after adding the animation to the model, I can't control (translate, rotate, scale) the model by gesture anymore.

Question 2: How can I keep controlling by gesture after adding the animation?

Answer 1

If you need the equivalent of SceneKit's .repeatForever action in RealityKit framework, use just a positive or negative .pi value rather than double PI. To control the speed of rotation, use duration parameter of FromToByAnimation struct.

model.transform.rotation = .init(angle: .pi, axis: [1, 1, 0])