title: CATransform3DRotate with m34 parameter need to know angle to fit specific height
body: <p>I have the following transform code:</p>
  
  <pre><code>//preparing transform
  CATransform3D basicTrans = CATransform3DIdentity;
  basicTrans.m34 =1.0/-projection;
  
  //calculating angle
  double angle= [[self angleValueForBlockHeight:height] doubleValue];
  double rangle;
  if (up)
  {
      rangle=angle/360*(2.0*M_PI);
  }
  else
  {
      rangle=(360.0-angle)/360*(2.0*M_PI);
  };
  
  
  //NSLog(@"    angle: %g", angle);
  
  //transforming
  bView.layer.transform = CATransform3DRotate(basicTrans, rangle, 1.0f, 0.0f, 0.0f);
  </code></pre>
  
  <p>As you can see I'm rotating bView using specific angle to have a value of height variable after rotation. And as you can see I have a angleValueForBlockHeight method there. This method has very ugly code.
  My question is how can I calculate the needed angle for this transform.
  The formula or the piece of code would be great.
  Help me , please.</p>
  
  <p>Thanks for your attention.</p>