Draw SceneKit object between two points

Question

Having made some progress in the geometry side of things I\'m moving on to putting together an entire scene. That scene has a couple dozen objects, each defined by a boundin

Answer 1

Draw the line between two nodes:

func generateLine( startPoint: SCNVector3, endPoint: SCNVector3) -> SCNGeometry {

        let vertices: [SCNVector3] = [startPoint, endPoint]
        let data = NSData(bytes: vertices, length: MemoryLayout.size * vertices.count) as Data

        let vertexSource = SCNGeometrySource(data: data,
                                             semantic: .vertex,
                                             vectorCount: vertices.count,
                                             usesFloatComponents: true,
                                             componentsPerVector: 3,
                                             bytesPerComponent: MemoryLayout.size,
                                             dataOffset: 0,
                                             dataStride: MemoryLayout.stride)

        let indices: [Int32] = [ 0, 1]

        let indexData = NSData(bytes: indices, length: MemoryLayout.size * indices.count) as Data

        let element = SCNGeometryElement(data: indexData,
                                         primitiveType: .line,
                                         primitiveCount: indices.count/2,
                                         bytesPerIndex: MemoryLayout.size)

        return SCNGeometry(sources: [vertexSource], elements: [element])

    }

How To Use

let line = generateLine(startPoint: SCNVector3Make(1, 1, 1), endPoint: SCNVector3Make(8, 8, 8))
        let lineNode = SCNNode(geometry: line)
        lineNode.position = SCNVector3Make(15, 15, 10)
        scene.rootNode.addChildNode(lineNode)

The thickness of the line requires implementing the SCNSceneRendererDelegate, in particular:

func renderer(_ renderer: SCNSceneRenderer, willRenderScene scene: SCNScene, atTime time: TimeInterval){
        glLineWidth(10)
}