DRD Team

In a recent session of GZDoom while testing out some weapons on the Monster Resource Wad, I noticed that at a certain distance from the wall, the dynamic lights of the standard bullet puff visibly jump left and create a copy at distances of roughly 128-256 mappixels (I didn't bother to count) the only things copied are the lights, the puffs remain in place. The copies disappear the closer you get to the wall. I'm not sure whether this consistently happens on all maps or just this one, but it seems to be a rendering error.

Some reference images:

Confirmed: it's level specific, but this may mean that something is wrong with the architecture of the level. I'm not absolutely sure what I'm talking about here, but it seems to me that the repetition of the small switch boxes in a single sector is causing the geometry of that sector to screw up and split improperly. I will attempt to document some other occurences if I am able to find them.

EDIT: In case I wasn't clear, I believe that the notes are being built incorrectly, or something similarly bizarre. Alternately, it may be that the sheer wall length is causing this incident.

If you could post the map I could look for myself.

Actually, just a few minutes ago I was playing another level when I noticed this same occurence. It is definitely connected to very long walls (>2000 pixels, or similarly large). I'll try to make a demo level, but it may be another ATI bug. It's strange that it only happens with the original bullet puff things, custom puffs don't have this problem.

EDIT: it's definitely a rendering error. Try playing NUTS with the no monsters flag on, you might see something similar. If you don't, it's probably something wrong with my graphics card. It only seems to work on walls placed parallel to the grid, and not at irregular angles.

Graf: It's the MRW's Monsters demo WAD. I can tell by the screens

The actual map doesn't matter, I've found the glitch in other maps as well.
Also, I mention that I was playing the monster demo in the original post.

I can't reproduce this. Can you post your system specs (graphics card etc.?)

Hmm...
Intel Celeron 1.80GHz, 640 MB RAM
Intel 82845G "Graphics Controller" (built into motherboard)
ATI Radeon 9250 with 128 MB RAM

and which of the graphics cards is active?

The ATI is active.