1、SCNAction简介
主要负责节点SCNNode的属性，实现node的渐变、移动、出现、消失、实现动画等。
2、相关API
- 节点的移动（earthNode的初始坐标（5，0，0））
//从当前位置移动指定的距离X轴：deltaX Y轴：deltaY Z轴：deltaZ+ (SCNAction *)moveByX:(CGFloat)deltaX y:(CGFloat)deltaY z:(CGFloat)deltaZ duration:(NSTimeInterval)duration;+ (SCNAction *)moveBy:(SCNVector3)delta duration:(NSTimeInterval)duration;
[self.earthNode runAction:[SCNAction moveByX:5 y:5 z:0 duration:1]]; [self.earthNode runAction:[SCNAction moveBy:SCNVector3Make(5, 5, 0) duration:1]];
//移动到指定坐标location+ (SCNAction *)moveTo:(SCNVector3)location duration:(NSTimeInterval)duration;
[self.earthNode runAction:[SCNAction moveTo:SCNVector3Make(5, 5, 0) duration:1]];
- 节点的旋转
//当前的节点基础上进行旋转指定的角度X轴：xAngle Y轴：yAngle Z轴：zAngle+ (SCNAction *)rotateByX:(CGFloat)xAngle y:(CGFloat)yAngle z:(CGFloat)zAngle duration:(NSTimeInterval)duration;//旋转到指定的角度X轴：xAngle Y轴：yAngle Z轴：zAngle//shortestUnitArc：YES是顺时针，NO为逆时针+ (SCNAction *)rotateToX:(CGFloat)xAngle y:(CGFloat)yAngle z:(CGFloat)zAngle duration:(NSTimeInterval)duration;+ (SCNAction *)rotateToX:(CGFloat)xAngle y:(CGFloat)yAngle z:(CGFloat)zAngle duration:(NSTimeInterval)duration shortestUnitArc:(BOOL)shortestUnitArc;
[self.earthNode runAction:[SCNAction rotateByX:0 y:M_PI_2 z:0 duration:4]]; dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(4 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{ [self.earthNode runAction:[SCNAction rotateToX:0 y:0 z:0 duration:4]]; });
//axis和原点组成轴向量，旋转angle角度//axisAngle：是四分量，前三个坐标相当于axis的值，第四个值为旋转角度+ (SCNAction *)rotateByAngle:(CGFloat)angle aroundAxis:(SCNVector3)axis duration:(NSTimeInterval)duration;+ (SCNAction *)rotateToAxisAngle:(SCNVector4)axisAngle duration:(NSTimeInterval)duration;
[self.earthNode runAction:[SCNAction rotateByAngle:M_PI_2 aroundAxis:SCNVector3Make(5, 5, 0) duration:4]];
[self.earthNode runAction:[SCNAction rotateToAxisAngle:SCNVector4Make(5, 5, 0, M_PI_2) duration:4]];
- 节点的缩放
//在原来基础上进行缩放+ (SCNAction *)scaleBy:(CGFloat)scale duration:(NSTimeInterval)sec;//在初始化的基础上进行缩放+ (SCNAction *)scaleTo:(CGFloat)scale duration:(NSTimeInterval)sec;
[self.earthNode runAction:[SCNAction scaleTo:2 duration:2]]; dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(2 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{ [self.earthNode runAction:[SCNAction scaleBy:0.5 duration:2]]; }); 
[self.earthNode runAction:[SCNAction scaleBy:2 duration:2]]; dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(2 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{ [self.earthNode runAction:[SCNAction scaleTo:0.5 duration:2]]; }); - 节点的透明度
//透明度变换到1的动画+ (SCNAction *)fadeInWithDuration:(NSTimeInterval)sec;//透明度变换到0的动画+ (SCNAction *)fadeOutWithDuration:(NSTimeInterval)sec;//原来的透明度基础上 变换值为factor+ (SCNAction *)fadeOpacityBy:(CGFloat)factor duration:(NSTimeInterval)sec;//变换到指定的透明度opacity+ (SCNAction *)fadeOpacityTo:(CGFloat)opacity duration:(NSTimeInterval)sec;
[self.earthNode runAction:[SCNAction fadeOutWithDuration:4]]; dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(2 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{ [self.earthNode runAction:[SCNAction fadeInWithDuration:2]]; }); - 节点的可视性
//隐藏node+ (SCNAction *)hide API_AVAILABLE(macos(10.11), ios(9.0));//不隐藏node+ (SCNAction *)unhide API_AVAILABLE(macos(10.11), ios(9.0));
- 移除节点
//移除节点+ (SCNAction *)removeFromParentNode;
- 添加音频播放
//播放音频。 waitForCompletion：YES Action的duration就是音频的时长；NO duration为0。+ (SCNAction *)playAudioSource:(SCNAudioSource *)source waitForCompletion:(BOOL)wait API_AVAILABLE(macos(10.11), ios(9.0));
- 创建节点的动画组或者重复节点的动画
//所有动画串行运行+ (SCNAction *)sequence:(NSArray*)actions;//所有动画并行运行+ (SCNAction *)group:(NSArray *)actions;//重复action动画，count次+ (SCNAction *)repeatAction:(SCNAction *)action count:(NSUInteger)count;//一直重复action动画+ (SCNAction *)repeatActionForever:(SCNAction *)action;
[self.earthNode runAction:[SCNAction group:@[[SCNAction rotateToX:5 y:5 z:0 duration:2],[SCNAction fadeOutWithDuration:2]]]];
[self.earthNode runAction:[SCNAction sequence:@[[SCNAction rotateToX:5 y:5 z:0 duration:2],[SCNAction fadeOutWithDuration:2]]]];
- 动画延迟设置（适用于//所有动画串行运行+ (SCNAction *)sequence:(NSArray<SCNAction *> *)actions;）
//动画延迟时间+ (SCNAction *)waitForDuration:(NSTimeInterval)sec;//动画延迟时间 随机数范围【sec，durationRange/2]+ (SCNAction *)waitForDuration:(NSTimeInterval)sec withRange:(NSTimeInterval)durationRange;
[self.earthNode runAction:[SCNAction sequence:@[[SCNAction rotateToX:5 y:5 z:0 duration:2],[SCNAction waitForDuration:2 withRange:6],[SCNAction fadeOutWithDuration:2]]]];
- 节点自定义动画
//执行动画开始时立即调用，node是正在动画的节点+ (SCNAction *)runBlock:(void (^)(SCNNode *node))block;+ (SCNAction *)runBlock:(void (^)(SCNNode *node))block queue:(dispatch_queue_t)queue;/** 反复运行脚本，直到动作的持续时间结束。每次SceneKit运行脚本时，它计算自操作开始执行以来的运行时间(作为操作在0.0到1.0之间的时间的一部分)，并使脚本作为一个名为elapsedTime的变量可用。 @param script 包含JavaScript源代码的字符串。 @param seconds 动作的持续时间，以秒为单位。 */+ (SCNAction *)javaScriptActionWithScript:(NSString *)script duration:(NSTimeInterval)seconds;/** 自定义动作执行时反复调用 @param seconds 动作时间 @param block 节点node，和动作开始经过的时间elapsedTime */+ (SCNAction *)customActionWithDuration:(NSTimeInterval)seconds actionBlock:(void (^)(SCNNode *node, CGFloat elapsedTime))block;
- 节点动画逆转
- (SCNAction *)reversedAction;
- 基础属性
//动画时间@property(nonatomic) NSTimeInterval duration;//定时模式@property(nonatomic) SCNActionTimingMode timingMode;
typedef NS_ENUM(NSInteger, SCNActionTimingMode) { SCNActionTimingModeLinear,//匀速 SCNActionTimingModeEaseIn,//先慢后快 SCNActionTimingModeEaseOut,//先快后慢 SCNActionTimingModeEaseInEaseOut//先慢中快后慢} API_AVAILABLE(macos(10.10), ios(8.0)); //使用这个输入来计算定制的计时功能，它的输出决定了动画的计时@property(nonatomic, nullable) SCNActionTimingFunction timingFunction;//自定义计时功能。输入时间在0.0到1.0之间。在行动期间。返回值必须为0-1.0并增加。当输入时间达到1.0时，函数必须返回1.0。typedef float (^SCNActionTimingFunction)(float time);
action.timingMode = SCNActionTimingModeLinear;action.timingFunction = ^float(float time) { return 1.0 - time*time;}; //速度系数@property(nonatomic) CGFloat speed;
- SCNActionable协议
//运行动画- (void)runAction:(SCNAction *)action API_AVAILABLE(macos(10.10));//运行动画，动画结束block块- (void)runAction:(SCNAction *)action completionHandler:(nullable void (^)(void))block API_AVAILABLE(macos(10.10));//运行动画设置key值- (void)runAction:(SCNAction *)action forKey:(nullable NSString *)key API_AVAILABLE(macos(10.10));//运行动画设置key值，动画结束block块- (void)runAction:(SCNAction *)action forKey:(nullable NSString *)key completionHandler:(nullable void (^)(void))block API_AVAILABLE(macos(10.10));//是否正在动画@property(nonatomic, readonly) BOOL hasActions API_AVAILABLE(macos(10.10));//通过key值获取动画- (nullable SCNAction *)actionForKey:(NSString *)key API_AVAILABLE(macos(10.10));//通过key值移除动画- (void)removeActionForKey:(NSString *)key API_AVAILABLE(macos(10.10));//移除所有动画- (void)removeAllActions API_AVAILABLE(macos(10.10));//读取所有动画key值@property(nonatomic, readonly) NSArray*actionKeys API_AVAILABLE(macos(10.10));