title: Incorrect work of SKPhysicsBody with moved SKSpriteNode anchorPoint?
body: <p>Here is my code:</p>
  
  <pre><code>    // setting background
  _ground = [[SKSpriteNode alloc]
                           initWithColor:[SKColor greenColor]
                                    size:CGSizeMake([Helpers landscapeScreenSize].width, 50)];
  _ground.name = @"ground";
  _ground.zPosition = 1;
  _ground.anchorPoint = CGPointMake(0, 0);
  _ground.position = CGPointMake(0, 0);
  _ground.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:CGSizeMake([Helpers landscapeScreenSize].width, 50)];
  _ground.physicsBody.dynamic = NO;
  _ground.physicsBody.affectedByGravity = NO;
  _ground.physicsBody.categoryBitMask = groundCategory;
  _ground.physicsBody.collisionBitMask = elementCategory;
  _ground.physicsBody.contactTestBitMask = elementCategory;
  </code></pre>
  
  <p>Green rectangle positioning is ok, but SKPhysicsBody is not representing this rectangle correctly. It looks like SKPhysicsBody is not "moving" its body according to sprite position and anchorPoint. SKPhysicsBody is moved left for _ground.width points.</p>
  
  <p><strong>What am I doing wrong?</strong></p>
  
  <p>PS.
  Changing to this (code) solved my problem, but I really dont like this solution, it seems an ugly way to position an element.</p>
  
  <pre><code>_ground.position = CGPointMake([Helpers landscapeScreenSize].width / 2, 0);
  </code></pre>
  
  <p>+removing:</p>
  
  <pre><code>_ground.position = CGPointMake(0, 0);
  </code></pre>