DNAっぽい二重螺旋を表示するiPhoneアプリのサンプルコード
import UIKit
import SceneKit
class ViewController: UIViewController,SCNSceneRendererDelegate {
weak var sceneView : SCNView?
override func viewDidLoad() {
super.viewDidLoad()
setupScene()
createCamera()
}
func setupScene() {
let sv = SCNView(frame: view.bounds)
sv.scene = SCNScene()
sv.backgroundColor = UIColor.blackColor()
sv.allowsCameraControl = true
sv.delegate = self
view.addSubview(sv)
sceneView = sv
}
func createHelix(i : Int) {
let r : Float = 0.1
let dw = Float(M_PI) / 50.0
var w = dw * Float(i)
var x = r * cos(w)
var z = r * sin(w)
let y = 0.01 * Float(i)
let bar = SCNBox(width: 0.01, height: 0.05, length: 0.01, chamferRadius: 0)
bar.firstMaterial?.diffuse.contents = UIColor.blueColor()
let barNodeA = SCNNode(geometry: bar)
barNodeA.position = SCNVector3(x: x, y: y, z: z)
self.sceneView?.scene?.rootNode.addChildNode(barNodeA)
w = dw * Float(i) + Float(M_PI/3.0)
x = r * cos(w)
z = r * sin(w)
let barB = SCNBox(width: 0.01, height: 0.05, length: 0.01, chamferRadius: 0)
barB.firstMaterial?.diffuse.contents = UIColor.orangeColor()
let barNodeB = SCNNode(geometry: barB)
barNodeB.position = SCNVector3(x: x, y: y, z: z)
self.sceneView?.scene?.rootNode.addChildNode(barNodeB)
if (i % 10 == 0) {
var verts : [SCNVector3] = [barNodeA.position, barNodeB.position];
let indices : [Int32] = [0, 1];
let vertexSource = SCNGeometrySource(vertices:UnsafePointer<SCNVector3>(verts), count:verts.count);
let indexData = NSData(bytes:indices, length:sizeof(Int32) * indices.count);
let element = SCNGeometryElement(data:indexData, primitiveType:.Line, primitiveCount:indices.count, bytesPerIndex:sizeof(Int32));
let line = SCNGeometry(sources:[vertexSource], elements:[element]);
line.firstMaterial?.diffuse.contents = UIColor(hue: 0.1, saturation: 0.4, brightness: 1, alpha: 1)
let lineNode = SCNNode(geometry:line);
sceneView?.scene?.rootNode.addChildNode(lineNode)
}
}
func createCamera() {
let camera = SCNNode()
camera.camera = SCNCamera()
camera.position = SCNVector3(x: 0, y: 1, z: 2.5)
sceneView?.scene?.rootNode.addChildNode(camera)
}
var count = 0
func renderer(aRenderer: SCNSceneRenderer, willRenderScene scene: SCNScene, atTime time: NSTimeInterval) {
glLineWidth(4)
}
func renderer(aRenderer: SCNSceneRenderer, updateAtTime time: NSTimeInterval) {
if (count < 300) {
self.createHelix(++count)
}
}
override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {
sceneView?.playing = true
}
}
extension Array {
func each(doit:T -> Void) { for i in self { doit(i); }}
}