advice on how to avoid rogue HOMs?

[Rexeljet]

Obviously the main way of avoiding HOMs is simply to texture every wall. Just putting that out there now so that nobody's wasting their time stating the obvious.


I've been having a go at making some levels in Zone Builder, and have noticed that rendering errors have a tendency to crop up in level maps, more specifically at doorway-type areas transitioning between an outdoor and indoor section.



Some examples of what I'm talking about:

On the offchance that it's of any use to anyone, here's a view of the area in the second picture (I abandoned the map seen in the first picture for other reasons) in an editor:

The HOM in this instance only appears from certain angles and distances, so it's probably not the end of the world if there isn't an easy solution (although the first example looked considerably worse), but since this doesn't seem to be a problem present in any of the base game's levels I assume there is some sort of method to prevent this from happening, even if it requires me to start again from scratch.

 

[Mr Beagle]

The first thing to look at is to make sure that all of the thok barrier sectors (that aren't over an entrance or exit) has the same values for the floor and the ceiling. Sometimes, the values can change on you when nearby sectors get created or merged.

The second thing is to use the official SRB2 levels as a guide on what direction the linedefs should be facing. Sometimes, playing with their direction can help.

The third thing is to go over and make sure every sector near the edge is split correctly. This can be ensured by using the "make sector tool" if you find one of them has more than one island. Edge sectors should not be sharing properties with those in a room's center (due to their specific function).

 

[Rexeljet]

I tried out the methods you suggested although none seemed to do anything- the thok barrier was just the one sector, all of the sectors were split properly, and I had a look at the official levels in Zone builder but there didn't really seem to be a standard regarding linedef directions for indoor-outdoor transitions. I tried flipping the relevant linedefs in various directions in my own level but nothing seemed to make a difference. But thanks for replying anyway.


However, I think I may have found what the problem was- I had originally placed the skybox and control sectors in the bottom right hand corner of the grid, far away from the actual level geometry. When I tried to ignore the HOM and continue to build the level, strange things started happening almost as if I was playing a corrupted game- the HOMs got worse (predictably), an invisible wall appeared in a completely flat part of the level, and when I tried to jump on a FOF I was sent spinning out of the level boundaries.


I did read that if you place control sectors and skyboxes too far away from the main level, the level will act strangely. I opened up some of the official maps again and noticed that indeed, these sectors tended to be quite close to the actual level geometry. So I moved the skybox and control sectors closer to the level in my own map (I switched back to an earlier version) and the HOMs I was experiencing before appear to be gone! Hopefully that's the problem sorted.