title: GLKit Object not rotating properly
body: <p>İ have a 3d object. </p>
  
  <p>i am rotating it with touches like this :</p>
  
  <pre><code>-(void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
  UITouch *touch = [touches anyObject];
  CGPoint location = [touch locationInView:self.view];
  CGPoint lastLoc = [touch previousLocationInView:self.view];
  CGPoint diff = CGPointMake(lastLoc.x - location.x, lastLoc.y - location.y);
  
  float rotX = -1 * GLKMathDegreesToRadians( diff.y / 2.0 );
  float rotY =  GLKMathDegreesToRadians( diff.x / 3.0 );
  
  
  GLKVector3 yAxis = GLKMatrix4MultiplyAndProjectVector3(GLKMatrix4Invert(_rotMatrix, &amp;isInvertible), GLKVector3Make(0, 0, 1) );
  _rotMatrix = GLKMatrix4Rotate(_rotMatrix, rotY, yAxis.x, yAxis.y, yAxis.z);
  
  GLKVector3 xAxis = GLKVector3Make(1, 0, 0);
  _rotMatrix = GLKMatrix4Rotate(_rotMatrix, rotX, xAxis.x, xAxis.y, xAxis.z);
  
  }
  </code></pre>
  
  <p>and setting matrices like this : </p>
  
  <pre><code>_modelViewMatrix = GLKMatrix4Identity;
  
  _modelViewMatrix = GLKMatrix4Translate(_modelViewMatrix, 0.0f, 0.0f, -60.0f);
  _modelViewMatrix = GLKMatrix4Translate(_modelViewMatrix, 0.0f, 5.5f, -4.0f);
  // i know i can to this by one code
  
  //çevirme işlemleri ilki klimanın kameraya doğru bakması için
  //ikincisi parmak hareketlerinden gelen transform matrisi
  // 90 derece döndermeyi kapatıyorum
  _modelViewMatrix = GLKMatrix4RotateX(_modelViewMatrix, GLKMathDegreesToRadians(90.0f));
  _modelViewMatrix = GLKMatrix4Multiply(_modelViewMatrix, _rotMatrix);
  
  _modelViewMatrix = GLKMatrix4Translate(_modelViewMatrix, 0.0f, -5.5f, +4.0f);
  
  self.reflectionMapEffect.transform.modelviewMatrix = _modelViewMatrix;
  </code></pre>
  
  <p>i am translating modelViewMatrix to objects centre. rotating it. than translating back. than translating -65 on z. but everytime i tried to do it. it's rotates like on the same vector. i think object has it's own centre. and rotating with it's own center and scene's center. </p>
  
  <p>how can i change object's centre with code or how can i rotate this object properly?</p>