title: SpriteKit: Collisions with 300 nodes, very low FPS
body: <p>I want to make a simple SpriteKit app where I can add "rocks" and they fall to bottom of the screen. Just like this: <a href="http://aamukasa.fi/II-13-347" rel="nofollow">http://aamukasa.fi/II-13-347</a>. The implementation is quite easy but I will get huge performance issues when there are more than 100 nodes. The FPS goes under 10 when all the blocks collides together. Is there anyway to achieve this kind of functionality with good FPS and about 300-400 blocks?</p>
  
  <pre><code>@implementation MyScene
  
  -(id)initWithSize:(CGSize)size {    
  if (self = [super initWithSize:size]) {
      /* Setup your scene here */
  
      self.backgroundColor = [SKColor colorWithWhite:1 alpha:1];
      self.physicsBody = [SKPhysicsBody bodyWithEdgeLoopFromRect:self.frame];
      self.scaleMode = SKSceneScaleModeAspectFit;
  
  
  }
  return self;
  }
  
  -(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
  /* Called when a touch begins */
  
  for (UITouch *touch in touches) {
      CGPoint location = [touch locationInNode:self];
  
      SKSpriteNode *rock = [[SKSpriteNode alloc] initWithColor:[SKColor blackColor]     size:CGSizeMake(20,10)];
      rock.position = location;
      rock.name = @"rock";
      rock.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:rock.size];
      [self addChild:rock];
  
  }
  }
  
  -(void)update:(CFTimeInterval)currentTime {
  /* Called before each frame is rendered */
  }
  
  @end
  </code></pre>