先看一下效果,太阳自转,地球绕着太阳转,月球绕着地球转,在项目开始时一定要在plist文件中添加对系统相机访问键值对,否则会崩溃

WechatIMG1.png

下面直接上代码.(OC)
/// 创建sceneView
@property (nonatomic, strong) ARSCNView *arSCNView;
/// 创建会话
@property (nonatomic, strong) ARSession *arSession;
/// 创建追踪(摄像头位置改变之后可以进行位置追踪)
@property (nonatomic, strong) ARConfiguration *arConfiguration;
/// 创建太阳节点
@property (nonatomic, strong) SCNNode *sunNode;
/// 创建地球节点
@property (nonatomic, strong) SCNNode *earthNode;
/// 创建月亮节点
@property (nonatomic, strong) SCNNode *moonNode;
/// 创建地月节点
@property (nonatomic, strong) SCNNode *earthGroupNode;

1. // 添加ARSCNView到View上(不要忘记懒加载创建arSCNView)

• (void)viewDidLoad {
  [super viewDidLoad];
  [self.view addSubview:self.arSCNView];
  }

• (void)viewWillAppear:(BOOL)animated {
  [super viewWillAppear:animated];
  // 创建追踪,因ARConfiguration是个基类不能直接初始化,所以要用他的子类
  /*
  API文档已经给出提示
  ARConfiguration is an abstract class; you do not create or work with instances of this class.
  To run an AR session, create an instance of the concrete
  */
  ARWorldTrackingConfiguration *trackingCongiguration = [[ARWorldTrackingConfiguration alloc] init];
  self.arConfiguration = trackingCongiguration;
  // 自适应灯光,(室内到室外,画面比较柔和)
  self.arConfiguration.lightEstimationEnabled = YES;
  // 加载配置
  [self.arSession runWithConfiguration:self.arConfiguration];
  }

2.运行程序就可以看到如下空白画面

WechatIMG2.jpeg

pragma mark ========== 初始化节点 ==========

• (void)initNode {
  self.sunNode = [[SCNNode alloc] init];
  self.earthNode = [[SCNNode alloc] init];
  self.moonNode = [[SCNNode alloc] init];
  self.earthGroupNode = [SCNNode node];

  self.sunNode.geometry = [SCNSphere sphereWithRadius:3.0];
  self.earthNode.geometry = [SCNSphere sphereWithRadius:1.0];
  self.moonNode.geometry = [SCNSphere sphereWithRadius:0.5];

  self.sunNode.geometry.firstMaterial.multiply.contents = @"sun.jpg";
  self.sunNode.geometry.firstMaterial.diffuse.contents = @"sun.jpg";
  // 强度
  self.sunNode.geometry.firstMaterial.multiply.intensity = 0.5;
  // 光照不变
  self.sunNode.geometry.firstMaterial.lightingModelName = SCNLightingModelConstant;
  // diffuse 扩散到 contents 全局
  self.earthNode.geometry.firstMaterial.diffuse.contents = @"earth-diffuse-mini.jpg";
  // emission 光、热等的）发射，散发；喷射；发行
  self.earthNode.geometry.firstMaterial.emission.contents = @"earth-emissive-mini.jpg";
  // specular 镜子的；会反射的；镜子一般的
  self.earthNode.geometry.firstMaterial.specular.contents = @"earth-specular-mini.jpg";
  // 光泽
  self.earthNode.geometry.firstMaterial.shininess = 0.1;
  // 反射多少光出去
  self.earthNode.geometry.firstMaterial.specular.intensity = 0.5;

  self.moonNode.geometry.firstMaterial.diffuse.contents = @"moon.jpg";

  // 重复渲染(可以试一下不添加这几句代码看下效果)从上到下,从左到右重复渲染
  /*
  SCNWrapMode是个枚举值有时间大家试一下,看一下效果

  SCNWrapModeClamp
  SCNWrapModeRepeat
  SCNWrapModeClampToBorder
  SCNWrapModeMirror
  */

  self.sunNode.geometry.firstMaterial.multiply.wrapS =
  self.sunNode.geometry.firstMaterial.diffuse.wrapS =
  self.sunNode.geometry.firstMaterial.multiply.wrapT =
  self.sunNode.geometry.firstMaterial.diffuse.wrapT = SCNWrapModeRepeat;

  // 确定节点位置
  self.sunNode.position = SCNVector3Make(0, 5, -30);
  self.earthNode.position = SCNVector3Make(0, 0, 0);
  self.moonNode.position = SCNVector3Make(2, 0, 0);
  self.earthGroupNode.position = SCNVector3Make(8, 0, 0);

  // 添加节点
  [self.arSCNView.scene.rootNode addChildNode:self.sunNode];

  [self.earthGroupNode addChildNode:self.earthNode];
  [self addSunNodeAnimation];
  [self rotationNode];
  }

pragma mark ========== 添加动画 ==========

// 太阳自转

• (void)addSunNodeAnimation {
  CABasicAnimation *sunBasicAnimation = [CABasicAnimation animationWithKeyPath:@"contentsTransform"];
  // 转一次的时间
  sunBasicAnimation.duration = 10.0;
  // 重复次数
  sunBasicAnimation.repeatCount = FLT_MAX;
  sunBasicAnimation.fromValue = [NSValue valueWithCATransform3D:CATransform3DConcat(CATransform3DMakeTranslation(0, 0, 0), CATransform3DMakeScale(1, 1, 1))];
  sunBasicAnimation.toValue = [NSValue valueWithCATransform3D:CATransform3DConcat(CATransform3DMakeTranslation(0, 0, 0), CATransform3DMakeScale(3, 3, 3))];
  [self.sunNode.geometry.firstMaterial.diffuse addAnimation:sunBasicAnimation forKey:@"sun animation"];
  }

// 公转

• (void)rotationNode {
  [self.earthNode runAction:[SCNAction repeatActionForever:[SCNAction rotateByX:0 y:1 z:0 duration:1]]];

  SCNNode *moonRotationNode = [SCNNode node];
  [moonRotationNode addChildNode:self.moonNode];

  CABasicAnimation *moonBasicAnimation = [CABasicAnimation animationWithKeyPath:@"rotation"];
  moonBasicAnimation.duration = 1.5;
  moonBasicAnimation.repeatCount = FLT_MAX;
  moonBasicAnimation.toValue = [NSValue valueWithSCNVector4:SCNVector4Make(0, 1, 0, M_PI * 2)];
  [self.moonNode addAnimation:moonBasicAnimation forKey:@"moon rotation"];

  CABasicAnimation *moonRotationAnimation = [CABasicAnimation animationWithKeyPath:@"rotation"];
  moonRotationAnimation.duration = 1;
  moonRotationAnimation.repeatCount = FLT_MAX;
  moonRotationAnimation.toValue = [NSValue valueWithSCNVector4:SCNVector4Make(0, 1, 0, M_PI * 2)];
  [moonRotationNode addAnimation:moonRotationAnimation forKey:@"moon rotation"];

  [self.earthGroupNode addChildNode:moonRotationNode];

  // 地球绕着太阳转
  SCNNode *earthSunRotationNode = [SCNNode node];
  [self.sunNode addChildNode:earthSunRotationNode];
  [earthSunRotationNode addChildNode:_earthGroupNode];

  // 月亮绕着地球转
  moonBasicAnimation = [CABasicAnimation animationWithKeyPath:@"rotation"];
  moonBasicAnimation.duration = 5;
  moonBasicAnimation.repeatCount = FLT_MAX;
  moonBasicAnimation.toValue = [NSValue valueWithSCNVector4:SCNVector4Make(0, 1, 0, M_PI * 2)];
  [earthSunRotationNode addAnimation:moonBasicAnimation forKey:@"earth rotation around sun"];
  }

pragma mark ========== 懒加载 ==========

• (ARSCNView *)arSCNView {
  if (!_arSCNView) {
  _arSCNView = [[ARSCNView alloc] initWithFrame:self.view.bounds];
  _arSCNView.delegate = self;
  _arSCNView.session = self.arSession;
  // 灯光自适应
  _arSCNView.automaticallyUpdatesLighting = YES;

    [self initNode];
  

  }
  return _arSCNView;
  }

• (ARSession *)arSession {
  if (!_arSession) {
  _arSession = [[ARSession alloc] init];
  }
  return _arSession;
  }

// 运行一下,看一下效果.是不是很炫.大家可以尝试着做一个七大行星的图谱.