iphone - 如何在 cocos2d 中获得跟随 Sprite 的粒子效果？

Question

我想要雪粒子效果跟随我的 Sprite ，我尝试了一些方法，但最终发生的只是雪将保持静止而不是跟随。我做了这个教程(我一找到它就会发布)，它展示了它如何用火来做，但根本没有成功。任何教程或建议将不胜感激。我相信我必须在代码片段部分添加某种代码，其中显示“在屏幕外创建敌人”。

   [self schedule:@selector(gameLogicboss:) interval:180 ];        
      [self schedule:@selector(updateboss:)];                

 -(void)addTarget1 {

     Boss *target1 = nil;    


     if ((arc4random() % 2) == 0) {{
      target1 = [WeakAndFastBoss boss];
   }}  else {
     target1 = [WeakAndFastBoss boss];
      }                      

       // Determine where to spawn the target along the Y axis
      CGSize winSize = [[CCDirector sharedDirector] winSize];
     int minY = target1.contentSize.height/2;
    int maxY = winSize.height - target1.contentSize.height/2;
    int rangeY = maxY - minY;
    int actualY = (arc4random() % rangeY) + minY;

  // Create the target slightly off-screen along the right edge,
      // and along a random position along the Y axis as calculated above
    target1.position = ccp(winSize.width + (target1.contentSize.width/2), actualY);
     [self addChild:target1 ];

       // Determine speed of the target

       int minDuration = target1.minMoveDuration;
       int maxDuration = target1.maxMoveDuration;
         int rangeDuration = maxDuration - minDuration;
          int actualDuration = (arc4random() % rangeDuration) + minDuration;

           // Create the actions
                                                                                                 id actionMove = [CCMoveTo actionWithDuration:actualDuration      position:ccp(-target1.contentSize.width/2, actualY)];


  id actionMoveDone = [CCCallFuncN actionWithTarget:self 
                                     selector:@selector(spriteMoveFinished:)];
 [target1 runAction:[CCSequence actions:actionMove, actionMoveDone, nil]];
  target1.tag = 1;
     [_targets addObject:target1];   
       }

 -(void)gameLogicboss:(ccTime)dt {
 [self addTarget1];
   iterations_++;
       }

                - (void)updateboss:(ccTime)dt {
        CGRect projectileRect = CGRectMake(projectile.position.x -                  (projectile.contentSize.width/2), projectile.position.y - (projectile.contentSize.height/2),                           projectile.contentSize.width,                                   projectile.contentSize.height);

BOOL bossHit = FALSE;
NSMutableArray *targetsToDelete = [[NSMutableArray alloc] init];
for (CCSprite *target1 in _targets) {
    CGRect target1Rect = CGRectMake(target1.position.x - (target1.contentSize.width/2),                                        target1.position.y - (target1.contentSize.height/2),                                        target1.contentSize.width,                                  target1.contentSize.height);

    if (CGRectIntersectsRect(projectileRect, target1Rect)) {

        //[targetsToDelete addObject:target];   
        bossHit = TRUE;
        Boss *boss = (Boss *)target1;
        boss.hp--;
        if (boss.hp <= 0) {
            _score ++;
            [targetsToDelete addObject:target1];
        }
        break;

    }                       
}

for (CCSprite *target in targetsToDelete) {
    [_targets removeObject:target];
    [self removeChild:target cleanup:YES];                                  
    _projectilesDestroyed++;
    if (_projectilesDestroyed > 2) {

          } 
         }

if (bossHit) {
    //[projectilesToDelete addObject:projectile];
    [[SimpleAudioEngine sharedEngine] playEffect:@"explosion.caf"];
}
[targetsToDelete release];
 }

     -(void)spriteMoveFinishedboss:(id)sender {
       CCSprite *sprite = (CCSprite *)sender;
      [self removeChild:sprite cleanup:YES];
       GameOverScene *gameOverScene = [GameOverScene node];
         [gameOverScene.layer.label setString:@"You Lose"];
       [[CCDirector sharedDirector] replaceScene:gameOverScene];    

      if (sprite.tag == 1) { // target
[_targets removeObject:sprite];
      } else if (sprite.tag == 2) { // projectile
[_projectiles removeObject:sprite];
     }
     }

Answer 1

我在 CCParticleSystem.h 找到了这个

/** @typedef tCCPositionType possible types of particle positions /typedef enum {    /* Living particles are attached to the world and are unaffected by emitter repositioning. */    kCCPositionTypeFree,
/** Living particles are attached to the world but will follow the emitter repositioning.
 Use case: Attach an emitter to an sprite, and you want that the emitter follows the sprite.
 */
kCCPositionTypeRelative,

/** Living particles are attached to the emitter and are translated along with it. */
kCCPositionTypeGrouped,
  
 

<p>you should set it like </p>

myparticleSystem.positionType=kCCPositionTypeGrouped;
 
  
希望有帮助。