I implemented an EntityAction to change the baseColor tint - and had it working on VisionOS 2.x.
import RealityKit
import UIKit
typealias Float4 = SIMD4<Float>
extension UIColor {
var float4: Float4 {
if
cgColor.numberOfComponents == 4,
let c = cgColor.components
{
Float4(Float(c[0]), Float(c[1]), Float(c[2]), Float(c[3]))
} else {
Float4()
}
}
}
struct ColourAction: EntityAction {
// MARK: - PUBLIC PROPERTIES
let startColour: Float4
let targetColour: Float4
// MARK: - PUBLIC COMPUTED PROPERTIES
var animatedValueType: (any AnimatableData.Type)? { Float4.self }
// MARK: - INITIATION
init(startColour: UIColor, targetColour: UIColor) {
self.startColour = startColour.float4
self.targetColour = targetColour.float4
}
// MARK: - PUBLIC STATIC FUNCTIONS
@MainActor static func registerEntityAction() {
ColourAction.subscribe(to: .updated) { event in
guard let animationState = event.animationState else { return }
let interpolatedColour = event.action.startColour.mixedWith(event.action.targetColour, by: Float(animationState.normalizedTime))
animationState.storeAnimatedValue(interpolatedColour)
}
}
}
extension Entity {
// MARK: - PUBLIC FUNCTIONS
func changeColourTo(_ targetColour: UIColor, duration: Double) {
guard
let modelComponent = components[ModelComponent.self],
let material = modelComponent.materials.first as? PhysicallyBasedMaterial
else {
return
}
let colourAction = ColourAction(startColour: material.baseColor.tint, targetColour: targetColour)
if let colourAnimation = try? AnimationResource.makeActionAnimation(for: colourAction, duration: duration, bindTarget: .material(0).baseColorTint) {
playAnimation(colourAnimation)
}
}
}
This doesn't work in VisionOS 26. My current fix is to directly set the material base colour - but this feels like the wrong approach:
@MainActor static func registerEntityAction() {
ColourAction.subscribe(to: .updated) { event in
guard
let animationState = event.animationState,
let entity = event.targetEntity,
let modelComponent = entity.components[ModelComponent.self],
var material = modelComponent.materials.first as? PhysicallyBasedMaterial
else { return }
let interpolatedColour = event.action.startColour.mixedWith(event.action.targetColour, by: Float(animationState.normalizedTime))
material.baseColor.tint = UIColor(interpolatedColour)
entity.components[ModelComponent.self]?.materials[0] = material
animationState.storeAnimatedValue(interpolatedColour)
}
}
So before I raise this as a bug, was I doing anything wrong in the former version and got lucky? Is there a better approach?
