SceneKit – Custom geometry does not show up

Question

I should see 2 yellow triangles, but I see nothing.

class Terrain {

    private class func createGeometry () -> SCNGeometry {

        let sources = [
           


        

Answer 1

Note: see Ash's answer, which is a much better approach for modern Swift than this one.

Your index array has the wrong size element. It's being inferred as [Int]. You need [CInt].

I broke out your elements setup into:

    let indices = [0, 2, 3, 0, 1, 2] // [Int]
    print(sizeof(Int))               // 8
    print(sizeof(CInt))              // 4
    let elements = [
        SCNGeometryElement(indices: indices, primitiveType: .Triangles)
    ]

To get the indices to be packed like the expected C array, declare the type explicitly:

    let indices: [CInt] = [0, 2, 3, 0, 1, 2]

Custom SceneKit Geometry in Swift on iOS not working but equivalent Objective C code does goes into more detail, but it's written against Swift 1, so you'll have to do some translation.

SCNGeometryElement(indices:, primitiveType:) doesn't appear to be documented anywhere, although it does appear in the headers.