How to free memory when moving between SpriteKit scenes - ios7

Question

I made a spritekit game with 10 different scenes with a single base scene which directs to each of the scenes. when I move to and from every scene, memory keeps going up, assuming due to texture caching, as explained here before.
The problem is that memory keeps going up to 300 MB and in weak devices it crashes after 3-4 scenes. I have tried to "free" memory using a cleanup function:
- (void)willMoveFromView:(SKView *)view {
[self.children enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
SKNode* child = obj;
[child removeAllActions];
}];
[self removeAllChildren];
}
However, this doesn't help. Any ideas how to solve this?
This is my main (and only) ViewController:
- (void)viewDidLoad
{
[super viewDidLoad];
// Configure the view.
SKView * skView = (SKView *)self.view;
// skView.showsFPS = YES;
skView.showsNodeCount = YES;
/* Sprite Kit applies additional optimizations to improve rendering performance */
skView.ignoresSiblingOrder = YES;
// Create and configure the scene.
MainMenu *scene = [MainMenu sceneWithSize: self.view.bounds.size];
scene.scaleMode = SKSceneScaleModeAspectFill;
// Present the scene.
[skView presentScene:scene];
}
and my switch to scene code:
- (void)switchToRoom
{
SKTransition *transition = [SKTransition fadeWithColor:[UIColor whiteColor] duration:0.5];
SKScene * scene = [[RoomScene alloc] initWithSize:self.size];
[self.view presentScene:scene transition:transition];
}
UPDATE:
After 3 days of struggling I found out that my bad practice was using a "curtain" styled animation to navigate between scenes. The problem with this method is that a "curtain" is at the size of the screen, and an Atlas of curtains with ~30 textures is HUGE, and probably what caused the memory to run so high, I am not sure why it caused a leak alike behavior, but when reducing the number of frames inside the atlas to around 10, I no longer see memory goes that high, and it looks like that there is no leak.
Another bad practice for this situation was to use "preloadTextures:textures" method, which appears to consume a lot of memory for this type of animation. When I removed it, performance became even better.

Answer 1

SK is suppose to take care of all that by itself baring you have a retain loop. However I too have run into this issue. My solution ended up being to manually set everything to nil:
-(void)willMoveFromView:(SKView *)view {
// for all arrays
[self.myArray removeAllObjects]; // and so on...
// for all objects
self.worldNode = nil;
self.player = nil; // and so on...
}
As you already stated, there will be some increase due to caching but you should level at some point. If this does not work, try running Instruments to see if you can spot a leak.