/**
* <code>rotateUpTo</code> is a utility function that alters the local rotation to point the Y
* axis in the direction given by newUp.
*
* @param newUp the up vector to use - assumed to be a unit vector.
*/
public void rotateUpTo(Vector3f newUp) {
TempVars vars = TempVars.get();
Vector3f compVecA = vars.vect1;
Quaternion q = vars.quat1;
// First figure out the current up vector.
Vector3f upY = compVecA.set(Vector3f.UNIT_Y);
Quaternion rot = localTransform.getRotation();
rot.multLocal(upY);
// get angle between vectors
float angle = upY.angleBetween(newUp);
// figure out rotation axis by taking cross product
Vector3f rotAxis = upY.crossLocal(newUp).normalizeLocal();
// Build a rotation quat and apply current local rotation.
q.fromAngleNormalAxis(angle, rotAxis);
q.mult(rot, rot);
vars.release();
setTransformRefresh();
}
