Odd texture behavior in PrBoom and Eternity

I'm in the process of testing a new project of mine using a few different types of source ports(ZDoom, Eternity, and PrBoom). One thing I don't understand is how Eternity and PrBoom handle certain textures when they are applied to sidedefs that are short(like 8-16 pixels tall). The only way for me to explain this is with pictures.

In the first picture, we have the offending wall, which is COMPTALL bordered with 8-pixel tall SUPPORT3 strips on the top and bottom.



The following pic shows me stepping underneath the SUPPORT3 strips in ZDoom. Nothing bad happens at all.



But in this next pic, I'm stepping underneath the SUPPORT3 strips in PrBoom(Eternity does this as well). Notice the distortion in the SUPPORT3 strip, like it's angling out. It flickers as I move also, which I can't show in a pic obviously.



So is this behavior due to the fact that PrBoom and Eternity are more closely emulating the vanilla DOOM behaviors? Obviously this wouldn't occur if I had used a STEP texture, so does it have to do with certain textures not being meant for short sidedefs? Any help would be appreciated. Thanks.

I don't think it's a question of texture size; I think it's an issue of precision for vertices that are behind the player's back, because it reminds me of this.

But Quasar said that Eternity was free of that bug, so maybe it's something else?

E: I typed this before you added the flickered pick. Now that's really weird. I have no idea.

You know when you place a mid texture in a space that's shorter than the height of the texture and it bleeds through the botton when you approach it? This sorta reminds me of that for some reason.

Vordakk said:

You know when you place a mid texture in a space that's shorter than the height of the texture and it bleeds through the botton when you approach it? This sorta reminds me of that for some reason.

I thought that only happens with fence-type textures, like MIDBARS3 or MIDGRATE.

Please post a shot of this happening in Eternity. It should not be happening.

Unless you're running a version of Eternity from, like, 2005 or something, that bug doesn't exist anymore.

Quasar said:

Please post a shot of this happening in Eternity. It should not be happening.

Hey, you were right! I upgraded to version 3.40.20 "Mjolnir" and this behavior doesn't occur anymore.

But just so I can get a clearer picture, is this bug due to my failures as a mapper or just a small flaw in PrBoom?

It's an old precision error dating back to vanilla. I'm not really sure why PrBoom+ doesn't fix it.

esselfortium said:

I'm not really sure why PrBoom+ doesn't fix it.

The OP only mentioned PrBoom (plus-less).

andrewj said:

The OP only mentioned PrBoom (plus-less).

You're right, I should be more specific. At the time of the screenshot I was running PrBoom Plus 2.5.1.1. I apologize if I was too vague before.

esselfortium said:

It's an old precision error dating back to vanilla. I'm not really sure why PrBoom+ doesn't fix it.

I'm not sure it's as easy to fix as you seem to imply.

andrewj said:

The OP only mentioned PrBoom (plus-less).

These days I assume they mean Plus even when they don't say so. With a certain sadness, admittedly.

It's not easy to fix ;) EE has a "little" thing called Cardboard, which is in many respects a new rendering engine.