I wanted to add a custom material over the mesh detected by the sceneReconstruction provider but i can't find a way to convert the meshAnchor to a usable MeshResource
func processReconstructionUpdates() async {
for await update in sceneReconstruction.anchorUpdates {
let meshAnchor = update.anchor
guard let shape = try? await ShapeResource.generateStaticMesh(from: meshAnchor)
else { continue }
switch update.event {
case .added:
let entity = ModelEntity(
mesh: **somehow get the mesh from mesh anchor here**,
materials: [material]
)
contentEntity.addChild(entity)
case .updated:
...
case .removed:
...
@unknown default:
fatalError("Unsupported anchor event")
}
}
}
Yeaaaah! I just figured this out today and posted on an older thread about it. The key for me was finding this repo: https://github.com/XRealityZone/what-vision-os-can-do/blob/main/WhatVisionOSCanDo/ShowCase/WorldScening/WorldSceningTrackingModel.swift#L70
Important code:
@MainActor fileprivate func generateModelEntity(geometry: MeshAnchor.Geometry) async throws -> ModelEntity {
// generate mesh
var desc = MeshDescriptor()
let posValues = geometry.vertices.asSIMD3(ofType: Float.self)
desc.positions = .init(posValues)
let normalValues = geometry.normals.asSIMD3(ofType: Float.self)
desc.normals = .init(normalValues)
do {
desc.primitives = .polygons(
// 应该都是三角形，所以这里直接写 3
(0..<geometry.faces.count).map { _ in UInt8(3) },
(0..<geometry.faces.count * 3).map {
geometry.faces.buffer.contents()
.advanced(by: $0 * geometry.faces.bytesPerIndex)
.assumingMemoryBound(to: UInt32.self).pointee
}
)
}
let meshResource = try await MeshResource.generate(from: [desc])
let material = SimpleMaterial(color: .red, isMetallic: false)
let modelEntity = ModelEntity(mesh: meshResource, materials: [material])
return modelEntity
}
