title: Change texture on SKSpriteNode
body: <p>I have an SKSpriteNode and I want to change the texture on it when the user touches the screen. But cannot work out how to do so.</p>
  
  <p>Creating and adding the head. (Declared in header).</p>
  
  <pre><code>    head = [SKSpriteNode spriteNodeWithImageNamed:[NSString stringWithFormat:@"%@",face]];
      head.position = CGPointMake(size.width / 2, size.height / 2);
      [self addChild:head];
  </code></pre>
  
  <p>When a touch is detected, the below is run, but I cannot work out how to apply it to the SKSpritenode?!</p>
  
  <pre><code>            SKAction* changeFace = [SKAction setTexture:[SKTexture textureWithImageNamed:[NSString stringWithFormat:@"%@",face]]];
              [self runAction:changeFace];
  </code></pre>
  
  <p>I have tried the below also, but it does not seem to work...</p>
  
  <pre><code>            head.texture = [SKTexture textureWithImageNamed:[NSString stringWithFormat:@"%@",face]];
  </code></pre>
  
  <p>Hope somebody is able to point me in the correct direction!</p>