Talk:Long wall error


AFAICT, this bug tends to occur only when (a) the player is very far away from the long wall and (b) the wall isn't perfectly north-south or east-west.  Therefore, I'm not sure it can be seen in any OEM level (a courtyard as big as the one in this demo would be an aesthetic crock even for TNT); if you disagree, please replace my file.  :>    Ryan W 23:13, 22 January 2006 (UTC)

I don't think this is correct. Look at MAP29 of Plutonia. The outside walls at the edge of the map are perfectly NS/EW and it still occurs. You can only really notice it if you are near one of the edges of the wall and facing toward the other edge. -Wagi
Not that anyone should value my opinion on technical questions, but frankly I don't see it in that map.  The dark pattern at the top of the wall texture only takes up a pixel or two, so the flickering is probably just roundoff causing that area to be rendered or not rendered in front of the sky texture.  At vanilla resolution the bug can't be observed at all, I suspect, because one pixel is the same height as an entire instance of the bug would be.
The distance between the end walls in Plutonia 29 is 8064 units, whereas in my DARKHELL.WAD example it is at least 12032 units.  Absent a code-based explanation, therefore, we must consider the possibility that the threshold is somewhere between those two values.  Or maybe it isn't, but the far wall of Plutonia 29 can only be viewed from certain angles (what with all those buildings in the way).  Or is there a demo that supports Wagi's argument?    Ryan W 13:44, 7 April 2008 (UTC)

I think the new image shows that Wagi is correct, above.  In my situation, rectangular segments would vanish and reappear at the top of the wall, the rest of which stayed put.  I'm having trouble reproducing it today (three OS changes later), but whatever it is, it belongs in a different article.    Ryan W (talk) 05:29, 28 January 2015 (UTC)