Wasn't it Les Patterson who wrote:
>There's something I don't understand about rotation.
>In the case of an aircraft positioned at 0,0,0(facing camera) then X, 
>and Z work fine, but rotate the aircraft to a right angle to the camera, 
>0,-90,0 and then X & Z don't rotate as expected. I understand that this 
>is a 360degree universe, but if that's the case then why wouldn't the 
>rotational angles be the same regardless of which direction the aircraft 
>is pointing?
>
>What is a good solution for "dipping" the wing when rotated 0,-90,0? The 
>only thing I've been able to do is change the angle of the nose of the 
>plane with either X or Z rotation. I know there is probably a simple 
>answer for this but it seems to escape me.

Let me make a bit of an educated guess that you are trying to do both
the Y rotation and the wing dip with a single rotation. Try doing it as
two separate rotations instead. 

Either
        rotate <0, 0, 20>       // wing dip
        rotate <0, -90, 0>      // turn
or
        rotate <0, -90, 0>      // turn
        rotate <20, 0, 0>       // wing dip

What happens is that POV performs the three components of rotation in
the order X,Y,Z. If you try to write it as "rotate <20, -90, 0>" then
the X rotation (currently nose angle) happens before the turn. If you
try to write it as "rotate <0, -90, 20>" then the Y rotation happens
first, and the Z rotation (which originally would have controlled the
wing dip) now affects the nose angle.

-- 
Mike Williams
Gentleman of Leisure

Post a reply to this message