Ios SceneKit逐顶点颜色

我一直在玩SceneKit，但我不知道如何创建逐顶点颜色几何体

更准确地说，我想这样做：

如果不清楚，请告诉我

谢谢。

倾倒信息：

    sceneView = SCNView(frame: sceneContainer.bounds)
    sceneView.scene = SCNScene()
    sceneView.allowsCameraControl = true
    sceneView.autoenablesDefaultLighting = true
    sceneView.showsStatistics = true
    sceneView.backgroundColor = UIColor.darkGrayColor()

    self.sceneContainer.addSubview(sceneView)

    // Vertex
    let vertices: [SCNVector3] = [SCNVector3(0, 0, 0),
        SCNVector3(1, 0, 0),
        SCNVector3(0.5, 1, 0)]

    let vertexData = NSData(bytes: vertices, length: vertices.count * sizeof(SCNVector3))
    let vertexSource = SCNGeometrySource(data: vertexData, semantic: SCNGeometrySourceSemanticVertex, vectorCount: vertices.count, floatComponents: true, componentsPerVector: 3, bytesPerComponent: sizeof(Float), dataOffset: 0, dataStride: sizeof(SCNVector3))

    // Faces
    let indices: [Int32] = [0,1,2]

    let indexData = NSData(bytes: indices, length: sizeof(Int32) * indices.count)
    let indexElement = SCNGeometryElement(data: indexData, primitiveType: SCNGeometryPrimitiveType.Triangles, primitiveCount: indices.count / 3, bytesPerIndex: sizeof(CInt))

    // Normals
    let normals: [SCNVector3] = [SCNVector3(0, 0, 1),
        SCNVector3(0, 0, 1),
        SCNVector3(0, 0, 1)]

    let normalData = NSData(bytes: normals, length: sizeof(SCNVector3) * normals.count)
    let normalSource = SCNGeometrySource(data: normalData, semantic: SCNGeometrySourceSemanticNormal, vectorCount: normals.count, floatComponents: true, componentsPerVector: 3, bytesPerComponent: sizeof(Float), dataOffset: 0, dataStride: sizeof(SCNVector3))

    // Colors
    let colors: [SCNVector3] = [SCNVector3(1, 0, 0),
        SCNVector3(0, 1, 0),
        SCNVector3(0, 0, 1)]

    let colorData = NSData(bytes: colors, length: sizeof(SCNVector3) * colors.count)
    let colorSource = SCNGeometrySource(data: colorData, semantic: SCNGeometrySourceSemanticColor, vectorCount: colors.count, floatComponents: true, componentsPerVector: 3, bytesPerComponent: sizeof(Float), dataOffset: 0, dataStride: sizeof(SCNVector3))

    // Geometry
    let voxelGeometry = SCNGeometry(sources: [vertexSource, normalSource, colorSource], elements: [indexElement])
    let voxelMaterial = SCNMaterial()
    voxelMaterial.diffuse.contents = UIColor.whiteColor()
    voxelGeometry.materials = [voxelMaterial]

    voxelNode = SCNNode(geometry: voxelGeometry)
    voxelNode.position = SCNVector3(0, 0, 0)

    sceneView.scene?.rootNode.addChildNode(voxelNode)

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我想我在这里发现了一些有趣的东西，SCNGeometrySource中的示例只讨论了顶点位置、法线和texCoord，但是还有颜色的语义，Swift 3需要一些小的更新。sizeof替换为MemoryLayout.size，语义参数可以是例如.color，您还可以使用Swift中的扩展函数隐藏许多低级C语言错误，例如``extension-SCNGeometrySource{便利init（data:[SCInvector3]，semantic:SCNGeometrySource.semantic）{let-dataData=NSData（bytes:data，length:data.count*MemoryLayout.size）self.init（data:dataData-as-data，semantic:semantic，vectorCount:data.count，usesFloatComponents:true，Components-Curvector:3，bytesPerComponent:MemoryLayout.size，dataOffset:0，dataStride:MemoryLayout.size）}```