CCSprite not displayed when placed on CCNode or position is wrong - objective-c

Question

I have this code in my init:
-(id)init {
if ((self = [super init])) {
CGSize screenSize = [CCDirector sharedDirector].winSize;
mapSize = CGSizeMake(4000, 4000);
rotateWorld = [CCNode node];
[rotateWorld setContentSize:mapSize];
rotateWorld.position = CGPointMake(screenSize.width / 2, screenSize.height / 2);
positionWorld = [CCNode node];
[positionWorld setContentSize:mapSize];
positionWorld.position = CGPointMake(mapSize.width / 2, mapSize.height / 2);
[rotateWorld addChild:positionWorld z:0];
[self addChild:rotateWorld z:0];
// Test enemy
[[CCSpriteFrameCache sharedSpriteFrameCache] addSpriteFramesWithFile:#"EnemiesSpritesheet.plist"];
spriteSheetNonPlayer = [[CCSpriteBatchNode alloc] initWithFile:#"EnemiesSpritesheet.png"capacity:10];
[positionWorld addChild:spriteSheetNonPlayer z:0];
enemy = [[Enemy_01 alloc] initWithSpriteFrame:[[CCSpriteFrameCache sharedSpriteFrameCache] spriteFrameByName:#"enemy_01_01.png"]];
enemy.position = CGPointMake(mapSize.width / 2, mapSize.height / 2);
[spriteSheetNonPlayer addChild:enemy];
}
return self;
}
Now I would expect my enemy sprite to show up in the middle of the screen, but it does not and I do not know if it is show at all. The funny thing is that if I change the positionWorld from a CCNode to a CCSprite containing a background image of 4000x4000 it works perfectly, but why not with a CCNode with its contetSize set? How do I get this to work with a CCNode?
Thank you
Søren

Answer 1

You need to set the anchorPoint to be ccp(0.5,0.5) for CCNode.
rotateWorld.anchorPoint = ccp(0.5f,0.5f);
positionWorld.anchorPoint = ccp(0.5f,0.5f);
CCSprite does the same thing internally in its init method (line 149 of CCSprite.m).