[Nel] culling and transforms

[Lionel Berenguier]

----- Original Message -----
From: <stephane.craux@voila.fr>
To: <nel@nevrax.org>
Sent: Saturday, June 30, 2001 12:21 PM
Subject: [Nel] culling and transforms


> Hi ,
> I Just took a look at nevrax code recently and
> noticed that rather than transforming AABB when traversing
> the scene graph , the choice was made to transform the
> view frustum pyramid : it is much more cpu costly :

Is it not nearly the same?

transform the planes:  transform 6 planes => 6*16= 96 muls.
transform the AABB:  transform 8 vectors => 8*12= 96 muls.

But maybe your trick to transform an AABB is to just transform the center
(12), then transform the 3 half vectors of the AABB (3*3 because of their
axis form), and then just do some add ?  (ooops :) )

regards

Lionel.