11/27/2000, Tech File Update
Here's a bit of info about what I've been doing lately. First the Davilex
stuff: The octree is fine now (never mentioned it in my techfile, but I did
post an image of the day). I used VTune to find some obsolete debugging code
that was eating 20% of my processor time, and I found that the c-buffer span
inserter actually wasn't the bottleneck as I suspected. The bottleneck
actually was the code that traced occluder polygon outlines, so I added
stuff to lower the number of inserted edges (using a winged edge structure).
O yeah, about winged edges: That's a structure that contains, for each
polygon edge, a pointer to the 'neighbour' polygon. You can use this
information to determine the outline of a shape: An edge contributes to the
outline if it's neighbour is invisible (not facing the camera). You can also
do lots of other stuff with it, but you get the basic idea now.
A dude from 3DS Max (forgot the name of the company) once sent me an e-mail
about this structure. Calculating the winged edge structure for a 1000
polygon mesh can be quite a lot of work: It involves checking every polygon
against every polygon. Well, not if you do it right, and that's exactly what
this dude told me: For each vertex, make a list of polygons that use it.
That's O(n) code. Now, if you want to determine the neighbouring polygon,
you know that it must be in the combined set of polygons of the two vertices
that make up the edge. So, now you determine the winged edge structure fast.
I've been doing other cool things as well, like programming my Nino (a WinCE
2.01 device). The thing has a 4 color greyscale LCD display, but it now
displays 32 shades. Actually, it runs the bilinear interpolated voxel
landscape demo that comes with the OpenPTC package. :) I couldn't believe my
eyes when I saw that running on such a small (and old!) device... The thing
is very fast, and it's a lot of fun to program it. So, if you own one, let
me know, I'll send you sources right away. :) I promised Jaap to do Lemmings
for it too, does anyone have a set of Lemmings animations for me? Otherwise
I'll be busy capturing screenshots from WinLemmings all day... :)
Greets - Phantom.
11/27/2000 - Tech File Update
09/30/2000 - Tech File Update
07/05/2000 - Tech File Update
06/26/2000 - Tech File Update
01/05/2000 - A Little Update For The Techfile
11/04/1999 - No Subject
07/26/1999 - No Subject
06/22/1999 - No Subject
06/15/1999 - No Subject
05/06/1999 - No Subject
05/05/1999 - No Subject
04/28/1999 - No Subject
04/26/1999 - Introduction
This document may not be reproduced in any way without
explicit permission from the author and flipCode. All Rights Reserved.
Best viewed at a high resolution.
The views expressed in this document are the views of the author and NOT neccesarily of anyone
else associated with flipCode.