ios - 我希望 SWIFT/Scenekit 中的所有对象在地板上都有阴影

Question

我正在 swift 开发一个 ARKit 项目。

在 SWIFT 中，我将对象添加到场景中。我想对这些对象做的是在它们下面显示一个阴影，使它们更逼真。我尝试了一些东西，但都没有用。我会在这里解释。

请理解我对 swift 还是个新手。我在 SWIFT 中以编程方式创建对象。我想我可以通过在所有物体下方创建一个不可见的平面并在场景上方放置一盏灯来做到这一点。我了解到，通过取消选中“写入颜色”值红色、绿色、蓝色和 alpha，我可以在 Xcode 的场景编辑器中的不可见平面上转换阴影。我在它上面放了一个聚光灯，它起作用了。现在我想以编程方式执行此操作。

我 swift 创建了灯光和平面，如下所示。我不再使用点了，因为场景太大了。这就是为什么我创造了一架非常大的飞机。我将它们添加到光的环境光和方向光中。环境所以它在侧面看起来不是黑色和方向性所以显示阴影。这不是。这些物体看起来奇怪地发光并且没有阴影。

let worldGroundPlaneGeometry = SCNPlane(width: 1000, height: 1000)
    worldGroundPlaneGeometry.firstMaterial?.colorBufferWriteMask = SCNColorMask(rawValue: 0)
    let worldGroundPlane = SCNNode()

    worldGroundPlane.geometry = worldGroundPlaneGeometry
    worldGroundPlane.position = worldPosition
    worldGroundPlane.castsShadow = true
    worldGroundPlane.eulerAngles = SCNVector3(Float.pi / 2, 0, 0)
    self.addChildNode(worldGroundPlane)

    // Create a ambient light
    let ambientLight = SCNNode()
    ambientLight.light = SCNLight()
    ambientLight.light?.color = UIColor.white
    ambientLight.light?.type = SCNLight.LightType.ambient
    ambientLight.position = SCNVector3(x: 0,y: 5,z: 0)

    // Create a directional light node with shadow
    let directionalNode = SCNNode()
    directionalNode.light = SCNLight()
    directionalNode.light?.type = SCNLight.LightType.directional
    directionalNode.light?.color = UIColor.white
    directionalNode.light?.castsShadow = true
    directionalNode.light?.automaticallyAdjustsShadowProjection = true
    directionalNode.light?.shadowSampleCount = 64
    directionalNode.light?.shadowMode = .deferred
    directionalNode.light?.shadowMapSize = CGSize(width: 2048, height: 2048)
    directionalNode.light?.shadowColor = UIColor.black.withAlphaComponent(0.75)
    directionalNode.position = SCNVector3(x: 0,y: 5,z: 0)

    // Add the lights to the container
    self.addChildNode(ambientLight)
    self.addChildNode(directionalNode)

它需要在整个场景中看起来像这样:

附言如果我在应用程序内的手机上渲染对象和阴影，它看起来是一样的。

我希望你能帮助我找到实现上述目标的解决方案。

希望你能帮帮我!谢谢😊

编辑:

下面提供的解决方案不是解决方案。现在我的场景看起来像这样，仍然没有阴影:

代码:

let worldGroundPlaneGeometry = SCNPlane(width: 1000, height: 1000)
    let worldGroundPlane = SCNNode()
    worldGroundPlane.geometry?.firstMaterial?.lightingModel = .constant
    worldGroundPlane.geometry?.firstMaterial?.writesToDepthBuffer = true
    worldGroundPlane.geometry?.firstMaterial?.colorBufferWriteMask = []
    worldGroundPlane.geometry = worldGroundPlaneGeometry
    worldGroundPlane.position = worldPosition
    worldGroundPlane.castsShadow = true
    worldGroundPlane.eulerAngles = SCNVector3(Float.pi / 2, 0, 0)
    self.addChildNode(worldGroundPlane)

    // Create a ambient light
    let ambientLight = SCNNode()
    ambientLight.light = SCNLight()
    ambientLight.light?.shadowMode = .deferred
    ambientLight.light?.color = UIColor.white
    ambientLight.light?.type = SCNLight.LightType.ambient
    ambientLight.position = SCNVector3(x: 0,y: 5,z: 0)

    // Create a directional light node with shadow
    let directionalNode = SCNNode()
    directionalNode.light = SCNLight()
    directionalNode.light?.type = SCNLight.LightType.directional
    directionalNode.light?.color = UIColor.white
    directionalNode.light?.castsShadow = true
    directionalNode.light?.automaticallyAdjustsShadowProjection = true
    directionalNode.light?.shadowSampleCount = 64
    directionalNode.light?.shadowMode = .deferred
    directionalNode.light?.shadowMapSize = CGSize(width: 2048, height: 2048)
    directionalNode.light?.shadowColor = UIColor.black.withAlphaComponent(0.75)
    directionalNode.position = SCNVector3(x: 0,y: 5,z: 0)

    // Add the lights to the container
    self.addChildNode(ambientLight)
    self.addChildNode(directionalNode)

Answer 1

我在玩弄你的照明设置，发现环境光使它看起来很褪色......而且阴影似乎太暗了。

无论如何，我将您的灯光设置配置调整为以下内容。我一起摆脱了环境光，并且在这种情况下我在对象节点(木箱)上添加了一个约束。我还只用一盏定向灯控制照明强度。

        let directionalNode = SCNNode()
        let constraint = SCNLookAtConstraint(target:node)
        directionalNode.light = SCNLight()
        directionalNode.light?.type = .directional
        directionalNode.light?.color = UIColor.white
        directionalNode.light?.castsShadow = true
        directionalNode.light?.intensity = 2000
        directionalNode.light?.shadowRadius = 16
        directionalNode.light?.shadowMode = .deferred
        directionalNode.eulerAngles = SCNVector3(Float.pi/2,0,0)
        directionalNode.light?.shadowColor = UIColor(red: 0, green: 0, blue: 0, alpha: 0.3)
        directionalNode.position = SCNVector3((node?.position.x)! + 10,(node?.position.y)! + 30,(node?.position.z)!+30)
        directionalNode.constraints = [constraint]
        // Add the lights to the container
        self.sceneView.scene.rootNode.addChildNode(directionalNode)