在SpriteKit中使用SKEmitterNode和粒子创建一个跟踪

Question

我试图让它变成这样一个粒子，只要玩家被移动，我就会跟随玩家。我试图复制的效果就像你在网站上，并且他们有一些跟随你的鼠标的对象。我尝试通过使粒子移动玩家所做的数量来做到这一点，但它没有再现预期的效果。有什么建议？我的代码：

声明粒子

NSString *myParticlePath = [[NSBundle mainBundle] pathForResource:@"trail" ofType:@"sks"];
self.trailParticle = [NSKeyedUnarchiver unarchiveObjectWithFile:myParticlePath];
self.trailParticle.position = CGPointMake(0,0);
[self.player addChild:self.trailParticle];

移动方法

 -(void)dragPlayer: (UIPanGestureRecognizer *)gesture {

         if (gesture.state == UIGestureRecognizerStateChanged) {

              //Get the (x,y) translation coordinate
              CGPoint translation = [gesture translationInView:self.view];

              //Move by -y because moving positive is right and down, we want right and up
              //so that we can match the user's drag location (SKView rectangle y is opp UIView)
              CGPoint newLocation = CGPointMake(self.player.position.x + translation.x, self.player.position.y - translation.y);
              CGPoint newLocPart = CGPointMake(self.trailParticle.position.x + translation.x, self.trailParticle.position.y - translation.y);

              //Check if location is in bounds of screen
              self.player.position = [self checkBounds:newLocation];
              self.trailParticle.position = [self checkBounds:newLocPart];
              self.trailParticle.particleAction = [SKAction moveByX:translation.x y:-translation.y duration:0];
              //Reset the translation point to the origin so that translation does not accumulate
              [gesture setTranslation:CGPointZero inView:self.view];

         }

    }

Answer 1

试试这个：

1）如果您的发射器位于场景中，请使用此发射器的属性targetNode并将其设置为场景。这意味着粒子不会是发射器的孩子，但你的场景应该留下痕迹..

不确定这是否正确（我在C＃中这样做）：

self.trailParticle.targetNode = self; // self as Scene

还有一些额外的：

2）我认为你可以把你的发射器作为孩子附加到self.player上，这样它就会自动与你的玩家一起移动，然后就不需要了：

self.trailParticle.position = [self checkBounds:newLocPart];
self.trailParticle.particleAction = [SKAction moveByX:translation.x y:-translation.y duration:0];

Answer 2

在更新循环中检查您的播放器是否沿X轴移动。然后在每次发生时创建一个精灵节点。在此示例中，您的播放器名称为“player1”。此处的关键是您的粒子必须在出生率附近的粒子列中设置最大值。吹码对我有用。

-(void)update:(CFTimeInterval)currentTime {
// Find your player
SKNode* Mynode = (SKSpriteNode *)[self childNodeWithName:@"player1"];  

// Check if our player is moving. Lower the number if you are not getting a trail. 
 if (Mynode.physicsBody.velocity.dx>10|
 Mynode.physicsBody.velocity.dy>10|
 Mynode.physicsBody.velocity.dx<-10|
 Mynode.physicsBody.velocity.dy<-10){       


// Unpack your particle
NSString *myParticlePath = [[NSBundle mainBundle] pathForResource:@"trail" ofType:@"sks"];

//Create your emitter
SKEmitterNode *myTrail = [NSKeyedUnarchiver unarchiveObjectWithFile:myParticlePath];

// This ensures your trail doesn't stay forever . Adjust this number for different effects
myTrail.numParticlesToEmit=10; 

// The length of your trail - higher number, longer trail. 
myTrail.particleLifetime = 2.0; 

//Set the trail position to the player position   
myTrail.position=Mynode.position;

//Add the trail to the scene
[self addChild:myTrail];
}

}