   Quaternion to degree....
  Hi,I'm making a 2D Mario like game and I want to use the Bullet-library for the physics. Bullet runs fine so far, but I have trouble with converting the quaternion rotation into degrees (Which Direct2D wants). Since it is 2D, I only need one axis (I think it's the Z-Component of the quaternion-vector). Here is what I tried, but it gives only half-correct results, so I think I do it wrong. [smile]
  I just found D3DXQuaternionToAxisAngle but I don't know how to use it...   ;  Use the quaternion to transform a vector (1,0,0), then take the transformed vector, ignore the Z component, and calculate atan2(Y,X) to obtain the angle around the Z axis the rotation represents.;  That worked, thank you!   