Hi, I'm developing an app for Vision Pro using Xcode, while updating the latest update, things that worked in my app suddenly didn't.
in my app flow I'm tapping spheres to get their positions, from some reason I get an offset from where I tap to where a marker on that position is showing up.
here's the part of code that does that, and a part that is responsible for an alignment that happens afterwards:
func loadMainScene(at position: SIMD3) async {
guard let content = self.content else { return }
do {
let rootEntity = try await Entity(named: "surgery 16.09", in: realityKitContentBundle)
rootEntity.scale = SIMD3<Float>(repeating: 0.5)
rootEntity.generateCollisionShapes(recursive: true)
self.modelRootEntity = rootEntity
let bounds = rootEntity.visualBounds(relativeTo: nil)
print("📏 Model bounds: center=\(bounds.center), extents=\(bounds.extents)")
let pivotEntity = Entity()
pivotEntity.addChild(rootEntity)
self.pivotEntity = pivotEntity
let modelAnchor = AnchorEntity(world: [1, 1.3, -0.8])
modelAnchor.addChild(pivotEntity)
content.add(modelAnchor)
updateModelOpacity(0.5)
self.modelAnchor = modelAnchor
rootEntity.visit { entity in
print("👀 Entity in model: \(entity.name)")
if entity.name.lowercased().hasPrefix("focus") {
entity.generateCollisionShapes(recursive: true)
entity.components.set(InputTargetComponent())
print("🎯 Made tappable: \(entity.name)")
}
}
print("✅ Model loaded with collisions")
guard let sphere = placementSphere else { return }
let sphereWorldXform = sphere.transformMatrix(relativeTo: nil)
var newXform = sphereWorldXform
newXform.columns.3.y += 0.1 // move up by 20 cm
let gridAnchor = AnchorEntity(world: newXform)
self.gridAnchor = gridAnchor
content.add(gridAnchor)
let baseScene = try await Entity(named: "Scene", in: realityKitContentBundle)
let gridSizeX = 18
let gridSizeY = 10
let gridSizeZ = 10
let spacing: Float = 0.05
let startX: Float = -Float(gridSizeX - 1) * spacing * 0.5 + 0.3
let startY: Float = -Float(gridSizeY - 1) * spacing * 0.5 - 0.1
let startZ: Float = -Float(gridSizeZ - 1) * spacing * 0.5
for i in 0..<gridSizeX {
for j in 0..<gridSizeY {
for k in 0..<gridSizeZ {
if j < 2 || j > gridSizeY - 5 { continue } // remove 2 bottom, 4 top
let cell = baseScene.clone(recursive: true)
cell.name = "Sphere"
cell.scale = .one * 0.02
cell.position = [
startX + Float(i) * spacing,
startY + Float(j) * spacing,
startZ + Float(k) * spacing
]
cell.generateCollisionShapes(recursive: true)
gridCells.append(cell)
gridAnchor.addChild(cell)
}
}
}
content.add(gridAnchor)
print("✅ Grid added")
} catch {
print("❌ Failed to load: \(error)")
}
}
private func handleModelOrGridTap(_ tappedEntity: Entity) {
guard let modelRootEntity = modelRootEntity else { return }
let localPosition = tappedEntity.position(relativeTo: modelRootEntity)
let worldPosition = tappedEntity.position(relativeTo: nil)
switch tapStep {
case 0:
modelPointA = localPosition
modelAnchor?.addChild(createMarker(at: worldPosition, color: [1, 0, 0]))
print("📍 Model point A: \(localPosition)")
tapStep += 1
case 1:
modelPointB = localPosition
modelAnchor?.addChild(createMarker(at: worldPosition, color: [1, 0.5, 0]))
print("📍 Model point B: \(localPosition)")
tapStep += 1
case 2:
targetPointA = worldPosition
targetMarkerA = createMarker(at: worldPosition,color: [0, 1, 0])
modelAnchor?.addChild(targetMarkerA!)
print("✅ Target point A: \(worldPosition)")
tapStep += 1
case 3:
targetPointB = worldPosition
targetMarkerB = createMarker(at: worldPosition,color: [0, 0, 1])
modelAnchor?.addChild(targetMarkerB!)
print("✅ Target point B: \(worldPosition)")
alignmentReady = true
tapStep += 1
default:
print("⚠️ Unexpected tap on model helper at step \(tapStep)")
}
}
func alignModel2Points() {
guard let modelPointA = modelPointA,
let modelPointB = modelPointB,
let targetPointA = targetPointA,
let targetPointB = targetPointB,
let modelRootEntity = modelRootEntity,
let pivotEntity = pivotEntity,
let modelAnchor = modelAnchor else {
print("❌ Missing data for alignment")
return
}
let modelVec = modelPointB - modelPointA
let targetVec = targetPointB - targetPointA
let modelLength = length(modelVec)
let targetLength = length(targetVec)
let scale = targetLength / modelLength
let modelDir = normalize(modelVec)
let targetDir = normalize(targetVec)
var axis = cross(modelDir, targetDir)
let axisLength = length(axis)
var rotation = simd_quatf()
if axisLength < 1e-6 {
if dot(modelDir, targetDir) > 0 {
rotation = simd_quatf(angle: 0, axis: [0,1,0])
} else {
let up: SIMD3<Float> = [0,1,0]
axis = cross(modelDir, up)
if length(axis) < 1e-6 {
axis = cross(modelDir, [1,0,0])
}
rotation = simd_quatf(angle: .pi, axis: normalize(axis))
}
} else {
let dotProduct = dot(modelDir, targetDir)
let clampedDot = max(-1.0, min(dotProduct, 1.0))
let angle = acos(clampedDot)
rotation = simd_quatf(angle: angle, axis: normalize(axis))
}
modelRootEntity.scale = .one * scale
modelRootEntity.orientation = rotation
let transformedPointA = rotation.act(modelPointA * scale)
pivotEntity.position = -transformedPointA
modelAnchor.position = targetPointA
alignedModelPosition = modelAnchor.position
print("✅ Aligned with scale \(scale), rotation \(rotation)")
Topic:
Spatial Computing
SubTopic:
General
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