如何在场景工具箱中显示金属和透明纹理？

Question

我无法在Scene Kit中显示一些纹理，这是我想使用的模型：

Sketchfab中的模型：https://skfb.ly/6QVTQ

使用Scene Kit在AR环境中，模型应以这些颜色和纹理显示。但是金色的笔尖显示为黑色，而透明的镜片根本不显示。是否有解决此问题的建议？

模型为.scn格式。这是模型材料的属性：https://drive.google.com/file/d/1HIHEsyONLXyL95dcSy9xWMGX89udMPND/view?usp=sharing

https://drive.google.com/file/d/1ndrZfcjqIQ4d2OfG6ZNvwyfDXnihJbnH/view?usp=sharing

如果您需要任何其他信息，请告诉我。预先谢谢你。

Answer 1

SceneKit中没有具有正确折射率的逼真的玻璃，但是您可以使用phong着色器轻松创建伪造的玻璃。对于金属材料，请使用physicallyBased阴影模型。

这里是代码：

import SceneKit

class ViewController: NSViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        let scene = SCNScene(named: "glasses.scn")!

        let sceneView = self.view as! SCNView
        sceneView.scene = scene
        sceneView.allowsCameraControl = true
        sceneView.backgroundColor = .black
        sceneView.pointOfView?.position.z = 20

        let glassesFrame = sceneView.scene?.rootNode.childNode(withName: "glassesFrame", 
                                                            recursively: true)

        glassesFrame?.geometry?.firstMaterial?.lightingModel = .physicallyBased
        glassesFrame?.geometry?.firstMaterial?.metalness.intensity = 1
        glassesFrame?.geometry?.firstMaterial?.diffuse.contents = NSColor.systemBrown

        let lens1 = sceneView.scene?.rootNode.childNode(withName: "rightLens", 
                                                     recursively: true)

        let lens2 = sceneView.scene?.rootNode.childNode(withName: "leftLens", 
                                                     recursively: true)

        let material = SCNMaterial()
        material.lightingModel = .phong
        material.diffuse.contents = NSColor(white: 0.2,
                                            alpha: 1)
        material.diffuse.intensity = 0.9
        material.specular.contents = NSColor(white: 1,
                                             alpha: 1)
        material.specular.intensity = 1.0
        material.reflective.contents = NSImage.Name("art.scnassets/texture.png")
        material.reflective.intensity = 2.0
        material.transparencyMode = .dualLayer
        material.fresnelExponent = 2.2
        material.isDoubleSided = true
        material.blendMode = .alpha
        material.shininess = 100
        material.transparency.native = 0.7
        material.cullMode = .back

        lens1?.geometry?.firstMaterial = material
        lens2?.geometry?.firstMaterial = material
    }
}