DESCRIPTION OF PROBLEM:
=======================
The example map, maps/disappearing_sliver3.map, contains an example of this
bug. The triangle sliver surface in the middle of the room is not rendered
in the final BSP.
To trigger the bug, compile the map; you don't need -vis or -light. Only
-bsp (the first q3map2 stage) is necessary to trigger the bug. The only
entities in the map are a light and a info_player_deathmatch, so the map will
compile for any Q3 mod.
SOLUTION TO PROBLEM:
====================
More work has been done to BaseWindingForPlane() to make it more accurate.
This function is in polylib.c. The changes to fix this regression test were
committed in revision 377; however, those changes are not "good enough".
IN-DEPTH DISCUSSION:
====================
This is the problem triangle:
In ParseRawBrush() for brush 0
Side 0:
(6144.000000 16122.000000 -2048.000000)
(6144.000000 16083.000000 -2048.000000)
(6784.000000 16241.000000 -2048.000000)
Computed winding before fix:
(6784.16406250 16241.04101562 -2048.00000000)
(6144.00000000 16122.00976562 -2048.00000000)
(6144.00000000 16083.00000000 -2048.00000000)
Obviously the 6784.16406250 is beyond epsilon error.
After revision 377:
(6783.85937500 16240.96484375 -2048.00000000)
(6144.00000000 16121.99218750 -2048.00000000)
(6144.00000000 16083.00000000 -2048.00000000)
Even though this fixes the regression test, the error in 6783.85937500 is
still greater than epsilon (but fortunately in the opposite direction). So
I don't consider this test case to be fixed quite yet.
