Unexpected HOM effect (Chocolate Doom)

Hey guys! Couldn't find this problem on the forums here, or anywhere else for that matter.

I've run into a snag. This discrepancy takes place in one of my vanilla maps (used a teleporter to make the fog act as reference):
http://imageshack.com/a/img28/8805/l7ec.png

Four giant mirror pillars and, by the looks of it, a small one covering the door on the right.

I ran the map in ZDoom to see if the problem lingered, but it looks fine:
http://imageshack.com/a/img15/4469/iqqa.png

Beyond the red line, it's all fine and dandy:
http://imageshack.com/a/img15/9739/u9zi.png

But when I reach this point, the effect takes place:
http://imageshack.com/a/img811/9493/zii4.png

I've checked the sectors all around the area, but there is nothing wrong with them. Tried changing node builders too, but the problem remains, albeit with varying results. It's safe to say that I have not reached a certain limit of linedefs, visplanes or anything similar. Where can I go from here? =(

CarpetolA said:

It's safe to say that I have not reached a certain limit of linedefs, visplanes or anything similar.

Are you sure? That looks like classic doom-limits HOM to me. Did you check it in chocorenderlimits or visplane explorer?

CarpetolA said:

It's safe to say that I have not reached a certain limit of linedefs, visplanes or anything similar. Where can I go from here? =(

How can you be so sure? The scene looks fairly complex (for vanilla), and the fact that it only kicks in when you stand back (and thus have more linedefs visible) is a clear indication that you're running out of drawsegs (an internal engine limit, basically you can't have more than 256 visible wall segments).

In general, drawsegs > linedefs for a given scene, and exactly how many you'll get depends on the node builder. Those curved walls and pipe/filter structures eat drawsegs like crazy -you may think it's just one line per wall, but to the engine there might be 4 or more.

And because segs are actually created from sidedefs, not linedefs, every 2-sided line is at minimum adding 2 segs to the scene. Anything behind the stone wall in the distance is counting towards that, too -- only a closed door or a 1-sided line will block the engine from continuing to step through any more segs.

Thank god for that Render Limit version of Chocolate Doom! The number of segs shown on the screen is too high. Now I'll have to crop the whole area... This sucks. Mapping for vanilla Doom seems to be more painstaking than I thought. =/

Thanks for the tools and your knowledge, guys! =)

Note that drawseg != BSP seg. Whilst you are indeed correct that additional linedef detail results in (many) more BSP segs, essel, it is not necessarily true that this will automatically result in more drawsegs at render time.

CarpetolA said:

Mapping for vanilla Doom seems to be more painstaking than I thought. =/

Oh indeed. Nothing makes you appreciate vanilla compatible levels like trying to make a few yourself. Good luck!

plums said:

Oh indeed. Nothing makes you appreciate vanilla compatible levels like trying to make a few yourself. Good luck!

Thanks! Here's the link to my project if you're interested:
http://www.doomworld.com/vb/wads-mods/65947-vanilla-e1-replacement-for-ultimate-doom/

I'm planning on shifting this whole thing towards a remaking of KDITD, so that means that I'll have to delete a couple of maps and make them from scratch again. Maybe I'm taking a coward's way out, but I feel comfortable that way. Of course I'll include my own parts and whatnot to the maps, but they will retain the familiar layouts of the original maps. The least I can do is emulate the visuals! =)