Strange chequered artifacting around transparencies in Fallout 3 / New Vegas

[brad86m]

Not sure what the cause is, but I have changed settings within the New Vegas launcher, and in DXVK config, but can't seem to fix this.

System information

• GPU: RTX 3090
• Driver: 526.86
• Wine version: n/a
• Windows version: 11
• DXVK version: 2.1

Without DXVK

With DXVK

[K0bin]

Looks like the game decided to use dithering instead of blending for some reason.

Please make two apitraces of the same scene. One with DXVK and one without.

[brad86m]

Absolutely will. Not sure how to apitrace, though.

[brad86m]

I have just found a post on Nexus mods mentioning that this is a bug since version 1.10.1

[Blisto91]

If you can send a savegame of the location i can look into making a trace. If i reproduce on AMD.

Edit: nvm it's the start of game i see and location is probably not relevant.

[K0bin]

I have just found a post on Nexus mods mentioning that this is a bug since version 1.10.1

In that case, someone could bisect it to find out which commit made the game do it.

[mbriar]

Isn't this the same as #3222?

[Blisto91]

Traces if needed
https://mega.nz/file/NwxGDLZJ#G2r7GCdbgWA328TlVzOQ57gU12vHE7tRU8rPOx5JniM

[Blisto91]

Isn't this the same as #3222?

Yes i think so.

From what i can tell this also isn't a regression in 1.10.1 but has looked like this ever since d9vk 0.30, which actually is closer to native than before that.

Apologize for the full desktop screenshots, Windows screenshots and dxvk doesn't work well for me.
Also apologize they are taken a bit far away from the tree but the issue disappears a bit when you get closer. Viewing at full size or a bit of zoom you should be able to spot it.
Lastly i don't know why the ground foliage moves around.

Screenshots

Native game

d9vk 0.22

d9vk 0.30

dxvk 2.1

[brad86m]

Thanks for looking deeper into it, guys. I wonder what it could be.

[DadSchoorse]

It's almost certainly alpha to coverage dithering. On radv it can be disabled with RADV_DEBUG=noatocdithering to get native d3d9 behavior (no dithering). To make it work by default and on more vendors we would need a vulkan extension, but that's very low on the priority list given the minor differences in visuals.

[JJones780]

Is it only with tree branches? I see this checkerboard texture affect with tree branches (only?) in IL2-Sturmovik as well. I have bigger issues when smoke appears - which has alpha but does not exhibit this dithered artifact so probably not related?

[neatodev]

There is no way to force dxvk to change behavior with the config file?

[K0bin]

Nope, there isn't. It would require changes to the Vulkan driver.

[dlpnd]

Tested with latest build, seems to be much better

https://cdn.discordapp.com/attachments/825404977965957200/1120948982567411814/image.png

[Blisto91]

Checking in game it seems to be exactly the same as before to me. It looks like you are standing too close in your screenshot.

Screenshot

[dlpnd]

I tried standing in the similar area, there may be some artifacting.

Here is a slider, I guess its not different https://imgsli.com/MTg3NzQ0 maybe its just the lighting. But it appears not as dark?