ZDoom

Thank you for the follow-up! Yeah that would certainly do it.

Followup: I figured it out! Somehow the Stereo 3d VR setting had been set to something other than Normal, and this seems to affect the display even when 3D VR is not in use. after flipping through a couple of the options there I found the angle was changing, and setting it back to Normal seems to have fixed the issue entirely.

Apologies for the thread, but now if someone else happens to encounter this, there's at least a note to check Display Options->Hardware Renderer->Stereo 3d VR and set 3d Mode to Normal

Works perfectly fine for me, btw on my Geforce 1060

Certainly. I've included a full driver report below, and I've attached my .ini file. One thing to note is prior to this a windows update had overwritten my GPU drivers, so I did a fresh install yesterday. Unfortunately this had no effect.

GPU - AMD Radeon VII - Primary/Discrete
VRAM - 16368 MB - HBM2 1000 MHz
Driver Version - 22.20.44-221025a-385558C-AMD-Software-PRO-Edition
AMD Windows Driver Version - 31.0.12044.3
Direct3D API Version - 12.1
Vulkan™ API Version - 1.3.217
OpenCL™ API Version - 2.0
OpenGL® API Version - 4.6
Direct3D® Driver Version - 9.14.10.01523
Vulkan™ Driver Version - 2.0.233
OpenCL® Driver Version - 31.0.12044.3
OpenGL® Driver Version - 22.10.220901_6eeec18
2D Driver Version - 8.1.1.1634
2D Driver File Path - /REGISTRY/MACHINE/SYSTEM/CurrentControlSet/Control/Class/{4d36e968-e325-11ce-bfc1-08002be10318}/0000
UI Version - 2022.1025.1410.1936
AMD Audio Driver Version - 10.0.1.24
Driver Provider - Advanced Micro Devices, Inc.
Windows Edition - Windows 11 Professional (64 bit)
Windows Version - 22H2

I'm going to move this to bugs then. This needs to be looked into by people who have the affected hardware. Can you let us know what drivers are you using, please? Also if you would be willing, a copy of your .ini would be helpful as well. Please feel free to search/remove any personal info (including your IRL name if it appears there) before posting it.

Thank you for the response, but unfortunately disabling lens distortion did not change anything. This bug occurs running vanilla doom, no mods, in both Vulkan and OpenGL modes on a Radeon VII. The screenshot (https://i.imgur.com/8t97nED.png) shows the bullet hole decal from a single shot on the pistol. I've created a quick and dirty video showing it in action here:
https://we.tl/t-Uy88hrLxNI
As you can see, single precise shots are all aiming to the right by a couple of degrees.

Do you have any mods loaded? In Vanilla Doom only the first shot will appear below the crosshair. Every subsequent shot will appear at an angle because the pistol is meant to be an inaccurate weapon. You can slow your shots down a lot (i.e. release the fire key and wait for the animation to finish on every shot) so that you never fire the pistol more than once at a time to get good pistol snipes, though.

Also try turning off the Lens Distortion in the Hardware->Postprocessing menu.

This bug is driving me crazy, and I don't know what to do about it.

Currently running GZDOOM 4.10 in Vulkan hardware mode with a Radeon VII. Completely vanilla otherwise, no mods loaded. Have also seen this issue with any mods loaded, as well as a copy of 4.9. For what it's worth, I am running three monitors (two on DisplayPort, one on HDMI) and this occurs on any screen I run it on.

Any weapon I fire (hitscan and projectiles alike) all fire offset to the right. In this screenshot (https://i.imgur.com/8t97nED.png), I've pointed out the crosshair and the resulting decal from a single first-fire shot from the pistol. I know that the 'hit' is not going to be exactly on the crosshair, as the 'camera' is located above the weapon line of fire, but it shouldn't be offset to the left or right (at least not on the first shot of a weapon). Changing resolutions, field of view, and fullscreen/windowed modes have no effect, but changing the renderer back to software fixes the issue. It occurs with both OpenGL and Vulkan modes.

Has anyone else encountered this? I've been digging through documentation (admittedly haphazardly) and forum posts, but the only thing I can find is the old "camera is above weapon line of fire" chestnut.