iPad Pro Lidar - Export Geometry & Texture

Question

I would like to be able to export a mesh and texture from the iPad Pro Lidar.

There\'s examples here of how to export a mesh, but Id like to be able to export the en

Answer 1

You need to compute the texture coordinates for each vertex, apply them to the mesh and supply a texture as a material to the mesh.

let geom = meshAnchor.geometry
let vertices = geom.vertices 
let size = arFrame.camera.imageResolution
let camera = arFrame.camera

let modelMatrix = meshAnchor.transform

let textureCoordinates = vertices.map { vertex -> vector_float2 in
    let vertex4 = vector_float4(vertex.x, vertex.y, vertex.z, 1)
    let world_vertex4 = simd_mul(modelMatrix!, vertex4)
    let world_vector3 = simd_float3(x: world_vertex4.x, y: world_vertex4.y, z: world_vertex4.z)
    let pt = camera.projectPoint(world_vector3,
        orientation: .portrait,
        viewportSize: CGSize(
            width: CGFloat(size.height),
            height: CGFloat(size.width)))
    let v = 1.0 - Float(pt.x) / Float(size.height)
    let u = Float(pt.y) / Float(size.width)
    return vector_float2(u, v)
}

// construct your vertices, normals and faces from the source geometry directly and supply the computed texture coords to create new geometry and then apply the texture.

let scnGeometry = SCNGeometry(sources: [verticesSource, textureCoordinates, normalsSource], elements: [facesSource])

let texture = UIImage(pixelBuffer: frame.capturedImage)
let imageMaterial = SCNMaterial()
imageMaterial.isDoubleSided = false
imageMaterial.diffuse.contents = texture
scnGeometry.materials = [imageMaterial]
let pcNode = SCNNode(geometry: scnGeometry)

pcNode if added to your scene will contain the mesh with the texture applied.

Texture coordinates computation from here