Scenekit - 将UIImage材质添加到自定义几何图形中

Question

我在ARKit中运行此功能，如果您试用它，则会出现三角形（非常高）和2右侧的摄像头，稍微平移一下。我的问题是，我的图像材料不能适用的对象，我可以改变它的颜色，但不适用的图像：

所以此工程：

triangle.firstMaterial?.diffuse.contents = UIColor.red 

但这并不：

triangle.firstMaterial?.diffuse.contents = UIImage(named: "wallpaper.jpg") 

这里是一个新鲜ARKit项目Xcode9完整视图控制器代码：

import UIKit 
import SceneKit 
import ARKit 

class ViewController: UIViewController, ARSCNViewDelegate { 

    @IBOutlet var sceneView: ARSCNView! 

    override func viewDidLoad() { 
     super.viewDidLoad() 

     sceneView.delegate = self 

     let scene = SCNScene() 

     let triangle = SCNGeometry.triangleFrom(vector1: SCNVector3(x: 0.059511181, y: -0.181795284, z: -0.0939711183), vector2: SCNVector3(x: 0.113824688, y: -0.181780666, z: -0.0674673915), vector3: SCNVector3(x: 0.113824688, y: 1.8182193, z: -0.0674673915)) 

     triangle.firstMaterial?.diffuse.contents = UIImage(named: "wallpaper.jpg") 

     let triangleNode = SCNNode(geometry: triangle) 

     triangleNode.name = "Triangle" 

     scene.rootNode.addChildNode(triangleNode) 

     sceneView.scene = scene 

    } 

    override func viewWillAppear(_ animated: Bool) { 
     super.viewWillAppear(animated) 

     // Create a session configuration 
     let configuration = ARWorldTrackingSessionConfiguration() 

     // Run the view's session 
     sceneView.session.run(configuration) 
    } 

    override func viewWillDisappear(_ animated: Bool) { 
     super.viewWillDisappear(animated) 
     sceneView.session.pause() 
    } 

} 

extension SCNGeometry { 
    class func triangleFrom(vector1: SCNVector3, vector2: SCNVector3, vector3: SCNVector3) -> SCNGeometry { 

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

     let source = SCNGeometrySource(vertices: [vector1, vector2, vector3]) 

     let element = SCNGeometryElement(indices: indices, primitiveType: .triangles) 

     return SCNGeometry(sources: [source], elements: [element]) 
    } 
} 

我没有包含的唯一的东西是纹理图像，但下载的任何图像都可以。

感谢

Answer 1

为了能够将纹理映射到你的几何形状，SceneKit需要有语义.texcoord几何源除了刚才您顶点的位置。