swift – SceneKit – 自定义几何体不显示

概述我应该看到2个黄色三角形,但我什么也看不见. class Terrain { private class func createGeometry () -> SCNGeometry { let sources = [ SCNGeometrySource(vertices:[ SCNVector3(x: -1.0, 我应该看到2个黄色三角形,但我什么也看不见.

class Terrain {    private class func createGeometry () -> SCNGeometry {        let sources = [            SCNGeometrySource(vertices:[                SCNVector3(x: -1.0,y: -1.0,z:  0.0),SCNVector3(x: -1.0,y:  1.0,SCNVector3(x:  1.0,z:  0.0)],count:4),SCNGeometrySource(normals:[                SCNVector3(x:  0.0,y:  0.0,z: -1.0),SCNVector3(x:  0.0,z: -1.0)],count:4)        ]        let elements = [            SCNGeometryElement(indices: [0,2,3,1,2],primitiveType: .Triangles)        ]        let geo = SCNGeometry(sources:sources,elements:elements)        let mat = SCNMaterial()        mat.diffuse.contents = UIcolor.yellowcolor()        mat.doubleSIDed = true        geo.materials = [mat]        return geo    }    class func createNode () -> SCNNode {        let node = SCNNode(geometry: createGeometry())        node.name = "Terrain"        node.position = SCNVector3()        return node    }}

我用它如下：

let terrain = Terrain.createNode()sceneVIEw.scene?.rootNode.addChildNode(terrain)let camera = SCNCamera()camera.zFar = 10000self.camera = SCNNode()self.camera.camera = cameraself.camera.position = SCNVector3(x: -20,y: 15,z: 30)let constraint = SCNLookAtConstraint(target: terrain)constraint.gimbalLockEnabled = trueself.camera.constraints = [constraint]sceneVIEw.scene?.rootNode.addChildNode(self.camera)

我看到其他节点具有非自定义几何体.怎么了？

注意：请参阅Ash的答案,对于现代Swift而言,这是一个比这个更好的方法.

您的索引数组具有错误的size元素.它被推断为[Int].你需要[CInt].

我将你的元素设置分解为：

let indices = [0,2] // [Int]    print(sizeof(Int))               // 8    print(sizeof(CInt))              // 4    let elements = [        SCNGeometryElement(indices: indices,primitiveType: .Triangles)    ]

要使索引像预期的C数组一样打包,请显式声明类型：

let indices: [CInt] = [0,2]

Custom SceneKit Geometry in Swift on iOS not working but equivalent Objective C code does更详细,但它是针对Swift 1编写的,所以你必须做一些翻译.

SCNGeometryElement(indices：,primitiveType :)似乎没有在任何地方记录,尽管它确实出现在标题中.

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