如何在 SceneKit 中实现逼真的景深效果？

Question

我正在尝试渲染具有逼真景深效果的帧。我已经在camera节点中尝试了景深属性，但它没有产生可用的结果。

是否可以切换到景深效果的最大渲染质量？性能不是一个因素，我只需要渲染一个帧，用户可以等待它。

Answer 1

SceneKit 中的真实景深效果

在 SceneKit 中，您可以轻松实现酷炫shallow/deep景深 (DoF)。而且它的加工强度不是很大。.focusDistance和.fStop参数对于应用 DoF 至关重要：

cameraNode.camera?.wantsDepthOfField = true
cameraNode.camera?.focusDistance = 5
cameraNode.camera?.fStop = 0.01
cameraNode.camera?.focalLength = 24

使用以下代码进行测试（macOS 版本）：

import SceneKit
import Cocoa

class GameViewController: NSViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        let scene = SCNScene()
        
        let cameraNode = SCNNode()
        cameraNode.camera = SCNCamera()
        cameraNode.camera?.wantsDepthOfField = true
        cameraNode.camera?.focusDistance = 5
        cameraNode.camera?.fStop = 0.01
        cameraNode.camera?.focalLength = 24
        scene.rootNode.addChildNode(cameraNode)
        cameraNode.position = SCNVector3(x: 0, y: 0, z: 15)
        
        let lightNode = SCNNode()
        lightNode.light = SCNLight()
        lightNode.light!.type = .omni
        lightNode.position = SCNVector3(x: 0, y: 10, z: 10)
        scene.rootNode.addChildNode(lightNode)
        
        let ambientLightNode = SCNNode()
        ambientLightNode.light = SCNLight()
        ambientLightNode.light!.type = .ambient
        ambientLightNode.light!.color = NSColor.darkGray
        scene.rootNode.addChildNode(ambientLightNode)
        
        let cylinderNode01 = SCNNode()
        cylinderNode01.geometry = SCNCylinder(radius: 2, height: 10)
        cylinderNode01.position = SCNVector3(0, 0, 0)
        cylinderNode01.geometry?.materials.first?.diffuse.contents = NSImage(named: NSImage.Name("checker01.png"))
        scene.rootNode.addChildNode(cylinderNode01)
        
        let cylinderNode02 = SCNNode()
        cylinderNode02.geometry = SCNCylinder(radius: 2, height: 10)
        cylinderNode02.position = SCNVector3(5, 0, 5)
        cylinderNode02.geometry?.materials.first?.diffuse.contents = NSImage(named: NSImage.Name("checker02.jpg"))
        scene.rootNode.addChildNode(cylinderNode02)
        
        let cylinderNode03 = SCNNode()
        cylinderNode03.geometry = SCNCylinder(radius: 2, height: 10)
        cylinderNode03.position = SCNVector3(10, 0, 10)
        cylinderNode03.geometry?.materials.first?.diffuse.contents = NSImage(named: NSImage.Name("checker01.png"))
        scene.rootNode.addChildNode(cylinderNode03)
        
        let cylinderNode04 = SCNNode()
        cylinderNode04.geometry = SCNCylinder(radius: 2, height: 10)
        cylinderNode04.position = SCNVector3(-5, 0, -5)
        cylinderNode04.geometry?.materials.first?.diffuse.contents = NSImage(named: NSImage.Name("checker02.jpg"))
        scene.rootNode.addChildNode(cylinderNode04)
        
        let cylinderNode05 = SCNNode()
        cylinderNode05.geometry = SCNCylinder(radius: 2, height: 10)
        cylinderNode05.position = SCNVector3(-10, 0, -10)
        cylinderNode05.geometry?.materials.first?.diffuse.contents = NSImage(named: NSImage.Name("checker01.png"))
        scene.rootNode.addChildNode(cylinderNode05)
       
        let scnView = self.view as! SCNView
        scnView.scene = scene
        scnView.allowsCameraControl = true
        scnView.backgroundColor = NSColor.black
    }
}