将SCNLight添加到SCNNode会使SCNNode变黑

Question

我正在尝试将SCNLight添加到SceneKit中的SCNSphere (SCNNode)。它的效果令人惊叹，唯一的问题是SCNLight所连接的源球体是完全黑色的，因为作为源，它根本得不到任何光。如何确保光源(即球体)完全亮起？

这是光源代码：

public func addLightSource(position: SCNVector3) -> SCNLight {
        let light = SCNLight()
        light.type = .omni
        light.intensity = 5000
        light.temperature = CGFloat(3500)
        return light
}

以及以后的

ParentNode.light = addLightSource(position: absolutePosition)

这是可行的，但会使ParentNode变黑。

Answer 1

为球体和灯光设置categoryBitMask实例属性以排除/包含它们：

func addLightSource(position: SCNVector3) -> SCNLight {
    let light = SCNLight()
    light.type = .omni
    light.intensity = 5000
    light.categoryBitMask = 1
    light.temperature = CGFloat(2000)
    return light
}

let sphereNode1 = SCNNode()
sphereNode1.geometry = SCNSphere(radius: 2)
sphereNode1.position = SCNVector3(x: 10, y: 0, z: 0)
sphereNode1.light = addLightSource(position: sphereNode1.position)
sphereNode1.categoryBitMask = 1
scene.rootNode.addChildNode(sphereNode1)