title: Flipping issue when interpolating Rotations using Quaternions
body: <p>I use slerp to interpolate between two quaternions representing rotations. The resulting rotation is then extracted as Euler angles to be fed into a graphics lib. This kind of works, but I have the following problem; when rotating around two (one works just fine) axes in the direction of the green arrow as shown in the left frame</p>
  
  <p><a href="http://img412.imageshack.us/img412/3425/sighe.jpg" rel="noreferrer">here</a> </p>
  
  <p>the rotation soon jumps around to rotate from the opposite site to the opposite visual direction, as indicated by the red arrow in the right frame.</p>
  
  <p>This may be logical from a mathematical perspective (although not to me), but it is undesired. How could I achieve an interpolation with no visual flipping and changing of directions when rotating around more than one axis, following the green arrow at all times until the interpolation is complete?</p>
  
  <p>Thanks in advance.</p>