Re: BSP edge list

Jim Bucher (
Wed, 19 Jun 1996 10:36:07 -0500

Date: Wed, 19 Jun 1996 10:36:07 -0500
From: Jim Bucher <>
Subject: Re: BSP edge list

Bernd Kreimeier wrote:

> You might maintain bool flags to indicate transformation has
> already been done, or you might flag all vertices in the PVS,
> and transform only those, or might transform all vertices in
> the leafs of the BSP actually reached during traversal...
> which would bring you back to your original problem.

I think the transformation flag is the best approach. In fact
I suggested this idea to Greg Lewis in email after he responded
that transforming all verts would be slow for large data sets. I
feel that the best idea would be to cull the scene as much as
possible and then transform the visible surfaces by going through
the surface and edge lists as Greg was doing. Except, instead of
transforming each vertex that you come to, first check the
transform flag to see if the vertex has already been processed.

> P.S.: is there really a non-closed polygon?

This was a mistake, I don't think there are any non-closed
surfaces. I meant to say that not all surfaces are polygons,
since some of them have holes.