Hi there,
I'm trying to merge the mesh anchor into a single mesh, but couldn't find any resources on this. Here is the code where I make the mesh from each mesh anchor, and assigned it to a model component with a shader graph material.
func run(_ sceneRec: SceneReconstructionProvider) async {
for await update in sceneRec.anchorUpdates {
switch update.event {
case .added, .updated:
// Get or create entity for this anchor
let anchorEntity = anchors[update.anchor.id] ?? {
let entity = ModelEntity()
root?.addChild(entity)
anchors[update.anchor.id] = entity
return entity
}()
// Remove any existing children
for child in anchorEntity.children {
child.removeFromParent()
}
// Generate the mesh from the anchor
guard let mesh = try? await MeshResource(from: update.anchor) else { return }
guard let shape = try? await ShapeResource.generateStaticMesh(from: update.anchor) else { continue }
print("Mesh added, vertices: \(update.anchor.geometry.vertices.count), bounds: \(mesh.bounds)")
// Get the material to use
var material: RealityKit.Material
if isMaterialLoaded, let loadedMaterial = self.shaderMaterial {
material = loadedMaterial
} else {
// Use a temporary material until the shader loads
var tempMaterial = UnlitMaterial()
tempMaterial.color = .init(tint: .purple.withAlphaComponent(0.5))
material = tempMaterial
}
await MainActor.run {
anchorEntity.components.set(ModelComponent(mesh: mesh, materials: [material]))
anchorEntity.setTransformMatrix(update.anchor.originFromAnchorTransform, relativeTo: nil)
// Add collision component with static flag - required for spatial interactions
anchorEntity.components.set(CollisionComponent(
shapes: [shape],
isStatic: true,
filter: .default
))
// Make entity interactive - enables spatial taps, drags, etc.
anchorEntity.components.set(InputTargetComponent())
let shadowComponent = GroundingShadowComponent(
castsShadow: true,
receivesShadow: true
)
anchorEntity.components.set(shadowComponent)
}
I then use a spatial tap gesture to set the position parameter in the shader graph material that creates a nice gradient from the tap position on the mesh to the rest of the mesh.
SpatialTapGesture()
.targetedToAnyEntity()
.onEnded { value in
let tappedEntity = value.entity
// Check if the tapped entity is a child of tracking.meshAnchors
if isChildOfMeshAnchors(entity: tappedEntity) {
// Get local position (in the entity's coordinate space)
let localPosition = value.location3D
// Convert to world position (scene coordinate space)
let worldPosition = value.convert(localPosition, from: .local, to: .scene)
print("Tapped mesh anchor at local position: \(localPosition)")
print("Tapped mesh anchor at world position: \(worldPosition)")
// Update the material parameter with the tap position
updateMaterialTapPosition(entity: tappedEntity, position: worldPosition)
} else {
print("Tapped entity is not a mesh anchor")
}
}
}
My issue is that because there are several mesh anchors, the gradient often gets cut off by the edge of the mesh generated from the mesh anchor as suppose to a nice continuous gradient across the entire scene reconstructed mesh I couldn't find any documentations on how to merge mesh from mesh anchors, any tips would be helpful! Thank you!
