Vulkan draws an "arrow"

[mty]

Hey,

I don't know if this qualifies as bug, but well, it shouldn't be there:

• This happens only with the Vulkan renderer.
• Geforce 1060 on a notebook
• I am running linux with nvidia-440. I just upgraded my graphic drivers from 410.
• My GZDoom version is: GZDoom g4.3pre-335-gfec280a5f

I made a Hexen map (udmf) with portals. Now when I am looking down, sometimes there is some "arrow" hole in the map, filled by sky. But just watch the video, it's easier than explaining it:



I removed custom assets. It's the same with all textures, sprites and 3d models loaded.
I also tried some things to fix it: before my map was over 32k units wide and tall, which created some other errors. So now some of the sloped 3d floors are messed up. But that arrow was there before, too.

Here is the wad:
http://www.matyy.de/doom/HEXMTY2-win2.zip

[Rachael]

Known bug - this is a problem with portal rendering, and it's one of the more vexing bugs. Every time it gets fixed it crops up again somehow.

It will do this in OpenGL too, and it's not like this hasn't been attempted to be fixed there as well.

[mty]

OK.

On my map it does not happen with OpenGL, tho. I couldn*t find no thread to it, I guess I am just missing the words to search for it. Should I append this map to some existing thread?

[Rachael]

Nah, leave it here. I'm sure someone will look at it but I don't know if anything can be done.

[Enjay]

As Rachael said, it looks like something that has been reported, fixed and then makes a return visit.

Here are two (fixed) instances that I reported of what looks like the same thing:

viewtopic.php?f=7&t=62518
viewtopic.php?f=7&t=63562

[Graf Zahl]

Sadly this isn't fully fixable, thanks to all the early portal hacks for ZDoom that took its sky-like behavior for granted. If this was changed a lot of mods would break.

[mty]

Thanks for the clarification. Is there any way to avoid it? Are the portals too complex? Too tall? Too big?


One more little video that shows an odd behaviour:


And it doesn't happen with OpenGL.

There are errors on the portal right now, but this is due to me trying to find a workaround by making the portals more square. And I am not done yet.

Here a picture of the map. From left to right it's almost 32k units. I heard that that is some limit.

[Graf Zahl]

This is not caused by the form of portals but by stacking multiple portals. For now I recommend not trying to work around it - this needs to be solved in the engine.