ペンローズの三角形

ペンローズの三角形を表示するiPhoneアプリのサンプルコード

#import “ViewController.h”

@import SceneKit;

@interface ViewController ()

@property (nonatomic, weak) SCNView *sceneView;

@end

@implementation ViewController

– (void)viewDidLoad {

    [super viewDidLoad];

    [self setupScene];

    [self createTriangle];

    [self createCamera];

}

– (void)setupScene {

    SCNView *sv = [[SCNView alloc] initWithFrame:self.view.bounds];

    sv.backgroundColor = [UIColor blackColor];

    sv.scene = [SCNScene scene];

    sv.allowsCameraControl = YES;

    sv.autoenablesDefaultLighting = YES;

    [self.view addSubview:sv];

    

    self.sceneView = sv;

}

– (void)createTriangle {

    

    SCNBox *barA = [SCNBox boxWithWidth:10 height:1 length:1 chamferRadius:0];

    barA.firstMaterial.diffuse.contents = [SCNNode nodeWithGeometry:barA];

    barA.firstMaterial.specular.contents = [UIColor whiteColor];

    SCNNode *barANode = [SCNNode nodeWithGeometry:barA];

    [self.sceneView.scene.rootNode addChildNode:barANode];

    

    SCNBox *barB = [SCNBox boxWithWidth:10 height:1 length:1 chamferRadius:0];

    barB.firstMaterial.diffuse.contents = [SCNNode nodeWithGeometry:barB];

    SCNNode *barBNode = [SCNNode nodeWithGeometry:barB];

    barBNode.pivot = SCNMatrix4Translate(barBNode.transform, 4.5, 0, 0);

    barBNode.transform = SCNMatrix4Rotate(barBNode.transform, M_PI/2.0, 0, 0, 1);

    barBNode.transform = SCNMatrix4Translate(barBNode.transform, –4.5, 0, 0);

    [self.sceneView.scene.rootNode addChildNode:barBNode];

    

    

    SCNBox *barC = [SCNBox boxWithWidth:6.5 height:1 length:1 chamferRadius:0];

    barC.firstMaterial.diffuse.contents = [SCNNode nodeWithGeometry:barC];

    SCNNode *barCNode = [SCNNode nodeWithGeometry:barC];

    barCNode.pivot = SCNMatrix4Translate(barCNode.transform, 3.5, 0, 0);

    barCNode.transform = SCNMatrix4Rotate(barCNode.transform, M_PI/2.0, 0, 1, 0);

    barCNode.transform = SCNMatrix4Translate(barCNode.transform, 4.5, 0, 0);

    [self.sceneView.scene.rootNode addChildNode:barCNode];

    

    SCNBox *plateC1 = [SCNBox boxWithWidth:2 height:1 length:0.1 chamferRadius:0];

    plateC1.firstMaterial.diffuse.contents = [UIColor whiteColor];

    SCNNode *plateC1Node = [SCNNode nodeWithGeometry:plateC1];

    plateC1Node.position = SCNVector3Make(-4, 0, 0.5);

    [barCNode addChildNode:plateC1Node];

    

    SCNBox *plateC2 = [SCNBox boxWithWidth:0.1 height:1 length:1 chamferRadius:0];

    plateC2.firstMaterial.diffuse.contents = [UIColor whiteColor];

    SCNNode *plateC2Node = [SCNNode nodeWithGeometry:plateC2];

    plateC2Node.position = SCNVector3Make(-5, 0, 0);

    [barCNode addChildNode:plateC2Node];

    

    UIBezierPath *path = [UIBezierPath bezierPath];

    [path moveToPoint:CGPointMake(0, 1)];

    [path addLineToPoint:CGPointMake(1, 0)];

    [path addLineToPoint:CGPointMake(1, 1)];

    [path closePath];

    SCNShape *shape = [SCNShape shapeWithPath:path extrusionDepth:0.1];

    shape.firstMaterial.diffuse.contents = [UIColor whiteColor];

    SCNNode *triangle = [SCNNode nodeWithGeometry:shape];

    triangle.position = SCNVector3Make(-4.2, 0.5, –0.5);

    triangle.rotation = SCNVector4Make(1, 0, 0, M_PI * 0.5);

    [barCNode addChildNode:triangle];

}

– (void)createCamera {

    SCNNode *camera = [SCNNode node];

    camera.name = @”camera”;

    camera.camera = [SCNCamera camera];

    camera.camera.zNear = 100;

    camera.camera.zFar = 150;

    camera.camera.yFov = 15;

    camera.position = SCNVector3Make(0, 0, 120);

    [self.sceneView.scene.rootNode addChildNode:camera];

}

@end