In RealiktKit we are creating objects with MeshResource but we are unable to set different materials for different faces

Using following blocks we are creating front and back of an entity. They are same polygons with some -z distance between them.

We see both side of it when we rotate entity in scene.

Looks like both side is applidedMaterial.

// FRONT var frontDesc = MeshDescriptor(name: "Front") frontDesc.positions = .init(frontPos) frontDesc.textureCoordinates = .init(uvs) frontDesc.primitives = .triangles(frontIndices.map(UInt32.init)) // BACK (reverse winding) var backDesc = MeshDescriptor(name: "Back") backDesc.positions = .init(backPos) backDesc.textureCoordinates = .init(uvs) backDesc.primitives = .triangles(frontIndices.reversed().map(UInt32.init)) let meshResource = try! MeshResource.generate(from: [frontDesc, backDesc]) let entity = ModelEntity(mesh: meshResource, materials: [applidedMaterial, menuMaterial])

ModelEntity(mesh: meshResource, materials: [applidedMaterial, menuMaterial]) does not work but why?

Also, when we change materials later like this

var frontMat = PhysicallyBasedMaterial() frontMat.baseColor = .init(texture: .init(globalSimpTexture[0])) frontMat.faceCulling = .none var backMat = PhysicallyBasedMaterial() backMat.baseColor = .init(texture: .init(globalSimpTexture[1])) backMat.faceCulling = .none piece.model?.materials = [frontMat, backMat]

both front and back have been set with frontMat