Path: chuka.playstation.co.uk!chuka.playstation.co.uk!news
From: "Alexander Jakes" <alex.jakes@dial.pipex.com>
Newsgroups: scee.yaroze.programming.3d_graphics
Subject: BSP trees and creating packets on the fly
Date: 22 Sep 1997 08:57:44 GMT
Organization: UUNET
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Message-ID: <01bcc373$67766900$d4f082c1@bass>
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Hello y'all,

I am currently playing with BSP trees for collision detection.  As a side
effect of this I have access to a list of ready sorted polygons that need
to be displayed.  I have a couple of questions regarding this:

1) Is it going to be quicker for me to let the Playstation draw the entire
scene  regardless of whether or not loads of it is out of view?

2) Assuming it is quicker to only draw the visible polygons supplied by my
BSP tree, can I add individual TMD primitives to the drawing list or do I
have to make a TMD data structure in memory containing the visible
primitives and then pass this to GsSortObject4.

3) If I make a ready sorted list of primitives in TMD format is their any
way to avoid the sort that GsSortObject4 does.  I assume the sort at least
will pass through all the data once even if it does not have to move
anything.

4) I have noticed there are functions for inserting lines into the display
list (GsSortLine, GsSortGLine).  Why are these available but a general
GsSortPrimitive is not?   

I assume the answer is that I need to make a new TMD object and thus have
duplicates of the world data I am BSPing.

Thanks,

Alex.