Re: 3d rotation question

[Roger H. <rog...@mi...>]

On Monday, June 21, 2004, at 03:40  pm, Keith Wiley wrote:

>
> I can't figure out how to take the present orientation (a quaternion 
> of course) and remove the vertical component of this orientation to 
> flatten it to 0 without affecting the horizontal orientation (so the 
> body is still looking along the same vertical azimuthal equator of the 
> world but at 0 degree altitude).  How do I do this?
>
>


Quesa's camera objects have a placement which has a camera position, a 
point of interest
and an up vector. If you set the Y value of the point of interest to 
the same Y value of the
camera position this should give you what you want. You might also want 
to set the up vector
to (0,1,0).