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 = 10000 self.camera = SCNNode() self.camera.camera = camera self.camera.position = SCNVector3(x: -20,y: 15,z: 30) let constraint = SCNLookAtConstraint(target: terrain) constraint.gimbalLockEnabled = true self.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.