Sprite kit 使用路径旋转精灵

嗨，我有一个精灵沿着一条贝塞尔曲线的路径，我希望精灵旋转到它当前移动的方向，我可以通过在中将

orientToPath

设置为

YES

来告诉它沿着路径

SKaction *enemyCurve = [SKAction followpath:cgpath asOffset:NO orientToPath:YES duration:5];

但这只会导致精灵面对运动的最后一点。有什么建议可以让它旋转到当前的方向吗？ 我已经包含了我用于下面路径的代码。谢谢你的帮助和建议

-(void)AddEnemy:(MotionType *)motion :(CGPoint*)Start :(CGPoint*)Finish :(EnemyType)enemyType{
double curTime = CACurrentMediaTime();

if (enemyType == One) {
    if(curTime > _nextAsteroidspawn)
    {
        float randSecs = [self randomValueBetween:0.20 andValue:1.0];
        _nextAsteroidspawn = randSecs + curTime;

        float randY = [self randomValueBetween:0.0 andValue:self.frame.size.height];
        float randDuration = [self randomValueBetween:2.0 andValue:10.0];


        SKSpriteNode *asteroid = [_Asteroids objectAtIndex:_nextAsteroid];
        _nextAsteroid++;

        if(_nextAsteroid >= _Asteroids.count){
            _nextAsteroid = 0;
        }



        [asteroid removeAllActions];
        asteroid.position = CGPointMake(self.frame.size.width+asteroid.size.width/2, 50);
        asteroid.hidden = NO;

        CGMutablePathRef cgpath = CGPathCreateMutable();

        CGPoint startingPoint = CGPointMake(self.frame.size.width+asteroid.size.width/2 , 50);

        CGPoint controlPoint1 = CGPointMake(160, 300);
        CGPoint controlPoint2 = CGPointMake(200, 600);

        CGPoint endingPoint = CGPointMake(0, self.frame.size.width - self.frame.size.width - asteroid.size.width / 2);

        CGPathMoveToPoint(cgpath, NULL, startingPoint.x, startingPoint.y);
        CGPathAddCurveToPoint(cgpath, NULL, controlPoint1.x, controlPoint1.y, controlPoint2.x
                              , controlPoint2.y, endingPoint.x
                              , endingPoint.y);


        SKAction *enemyCurve = [SKAction followPath:cgpath asOffset:NO orientToPath:YES duration:5];



        CGPoint location = CGPointMake(-self.frame.size.width-asteroid.size.width, randY);

        SKAction *moveAction = [SKAction moveTo:location duration:randDuration];
        SKAction *doneAction = [SKAction runBlock:(dispatch_block_t)^(){

            asteroid.hidden = YES;
        }];


        SKAction *moveAsteroidActionWithDone = [SKAction sequence:@[enemyCurve,moveAction, doneAction]];

        [asteroid runAction:moveAsteroidActionWithDone withKey:@"asteroidMoving"];

        CGPathRelease(cgpath);

        //[asteroid runAction: [SKAction repeatActionForever:[SKAction animateWithTextures:_Asteroids timePerFrame:0.1f]]];
    }

创建敌方节点的代码如下所示，我不对节点应用任何旋转

在初始尺寸中：

_Asteroids = [[NSMutableArray alloc] initWithCapacity:knumAsteroids];
        for(int i = 0; i < knumAsteroids; i++)
        {
            SKSpriteNode *asteroid = [SKSpriteNode spriteNodeWithImageNamed:@"enemyBasic1"];
            asteroid.hidden = YES;
            [_Asteroids addObject:asteroid];
            [self addChild:asteroid];
        }

---

更新中的方法仅链接到顶部发布的代码，该代码确定了敌人将采取的路径。我还更新了该方法，以包括整个方法。

使节点朝向特定的点。这个链接解释了我使用的精灵是如何用相同的代码自动旋转的。你在对敌方节点做其他事情吗？我建议你发布创建敌方节点的代码。嗨，很抱歉回复太晚，我已经更新了它，包括创建敌方节点的代码以及创建和应用路径的完整方法。你需要计算旋转角度，在物理更新方法中更新精灵的zRotation，至少我是这么做的。

[self AddEnemy:BezierCurve :NULL :NULL:One];