http://www.teaser.fr/~amajorel/doom/bsp23bug.zip
ftp://ftp.cdrom.com/pub/idgames/utils/node_builders/bsp23bug.zip


This (bsp23bug.wad) is a pwad that exercises what I think to be
two spectacular bugs in BSP 2.3. Recipe :

    1) At the start, look at the red wall in front of you.

    2) Outside, near the candle, you can see a red wall that
       shouldn't be there, since there is no linedef at that
       spot.  It's still solid enough to hide the dead marine
       behind it.  Also, for a psychedelic trip, take a walk
       along the long red wall nearby.

I've tested the wad with XDoom, LxDoom and the original Doom. I
think the bugs are in BSP 2.3, not in the wad or in Doom
because, when using Warm to build the nodes, they don't show.


Colin Phipps posted this on r.g.c.d.e. :

    "Well I booted The Other OS and did some investigating:

    - The bug occurs with the dos bsp v2.3 binaries on
      cdrom.com, or with bsp v2.3 compiled from the source. It
      is definitely a bug in making the nodes.

    - The bsp v1.5x dos binaries on cdrom.com generate similar
      nodes but without the bugs.

    - The bsp v3.0 dos binaries on cdrom.com generate slightly
      different nodes, without the bug.

    - Playing with -vp, the splitting factor etc, can force bsp
      v2.3 to generate a different pattern of nodes and hence
      avoid the bug.

    My compliments to nodenav for being a very convenient nodes
    viewer. The second bug mentioned in your text file shows up
    in nodenav well, it seems the node builder is making a
    repeated rounding error, which makes the segs get drawn down
    the split line. Doom's approximate coordinates strike again
    :-\."


It's unlikely that Lee Killough fixes BSP right now. If someone
wants to tackle the problem, he/she is highly welcome :-). Then
it might be the occasion to make a new release of BSP to
integrate the fix plus changes that Randy Heit, Udo Munk and me
have been doing. Tell us about it !

While talking about wishes, did you notice the perfect horizon
effect you see in the vicinity of the candle ? (see horizon.png)
I would be _very_ happy if someone hacked BSP to produce such
perfect "infinity" horizons in a controllable fashion.


History :

    1996-06-14  Initial release.
    1996-06-19  Included Colin's comments. Further stripped down
		the demo pwad (27 kB to 14 kB). Added
		horizon.wad. Uploaded a copy to ftp.cdrom.com.


-- André Majorel <amajorel@teaser.fr> 1999-06-19
