particles in particle systems behaves weird

Question

i have a node (named 'terrain') that i offset so that my main game object (my character) stays in the center of the screen. i do this like this:

 [_terrain setOffsetX:offsetX andOffsetY:offsetY*4/3];

the thing is that on my terrain, i have a particle system. When moving my character (and thus offsetting the terrain) the particles emitted are not mentaining their up-word trajectory. It looks like the particles emitted are dephased. Here is my particle system code that i include in my terrain class (i.e. self refers to the terrain itself) :

  emitterSnow = [CCParticleSnow node];
   emitterSnow.position = startPoint;
    [emitterSnow setAnchorPoint:CGPointZero];
    [self addChild:emitterSnow z:0 tag:windIndicatorTag];

    CGPoint p = emitterSnow.position;
    emitterSnow.position = ccp( p.x + width/2 , p.y);
    emitterSnow.life = 1;
    emitterSnow.lifeVar = .3f;
    [emitterSnow setIsRelativeAnchorPoint:YES];

     emitterSnow.posVar = CGPointMake(width/2,0);

    // gravity
    emitterSnow.gravity = ccp(0,1000);

    // speed of particles
    emitterSnow.speed = 140;
    emitterSnow.speedVar = 20;

    ccColor4F startColor = emitterSnow.startColor;
    startColor.r = 0.9f;
    startColor.g = 0.9f;
    startColor.b = 0.9f;
    emitterSnow.startColor = startColor;

    ccColor4F startColorVar = emitterSnow.startColorVar;
    startColorVar.b = 0.1f;
    emitterSnow.startColorVar = startColorVar;

    emitterSnow.emissionRate = 30;

    emitterSnow.texture = [[CCTextureCache sharedTextureCache] addImage: @"bubble2.png"];

How can i have my particles move up from my particle system source?

Answer 1

Try setting the positionType (a tCCPositionType). Use kCCPositionTypeFree (default one) for moving particles freely. Or use kCCPositionTypeGrouped to move them in a group.