Visual Bugs (on nvidia+Windows)

From https://twitter.com/natzaw_/status/1312745825517395971 and following, seem to affect both Vanilla Doom3 and dhewm3. As far as I understand some nvidia GPU, a 144Hz display and RTSS were involved, though apparently the bug also happens without RTSS. Enabling/disabling vsync doesn't seem to make a difference. Might just be a driver bug, but who knows.. The issues kinda remind me of #261, but com_fixedTic was 0, not -1 here.

(Quoting Nataniel's Tweets, adding my replies without quotes in between)

Found three more bugs.

During loading screens mouse cursor is visible and you can move it .

Visual bug on Communication level - screenshot included.

Weird candles shadow flickering on Hell levels - first one especially

that's a feature
ok
weird, do you know if it looks different to original/vanilla Doom3?

Ok. About 3. I will check it out with vanilla right now.

while at it, can you check 2 as well in vanilla?

Both of them are present in Doom 3 vanilla and dhewm3 replicate them perfectly. The thing is I don't recall ever seeing them on win xp (when the game came out originally) or win 7 when I last time played this. I've completed the game over 10 times so I know it pretty well :) (https://twitter.com/natzaw_/status/1312788111873716224 contains a video showing the flickering) Maybe they are the result of playing the game / source port on modern OS / new GPU drivers. They are not game breaking, it's that they look buggy. Like that shadow bug mentioned in the github issues section.

it seems like it flickers the same as RTSS - maybe the flickering goes away if you disable RTSS?

Tried that already ;) It flickers no matter what. That communication bug mentioned early also is present.

Good to know :) Did you change the value of com_fixedTic ? it should be 0 (setting it to -1 was assumed to allow 120Hz playing, but turned out to cause issues like flickering particles) Otherwise I'd say it's a driver bug - I mean this has worked for > 15 years and Doom3 used to be the game OpenGL drivers were optimized for (mostly because at that time most games already used Direct3D instead).

No. The only settings I've changed were in-game resolution to 1080p (vanilla and dhemw3) and fov to 110 (dhemw3 only). Other then that the same default config. 60fps cap set in RTSS.

hmm does enabling vsync help (if it isn't already)? (if it doesn't, does it help if you somehow tell the driver that vsync should enforce 60hz)?

setting a cap with RTSS shouldn't be necessary, Doom3 enforces (around) 60Hz by itself, and vsync should enforce exactly 60Hz

V-sync on or off makes no difference - bugs are always there. I usually turn v-sync off in-game (lower input lag) and set RTSS cap depending on the desired game frame rate. Since it's 144 hz g-sync monitor I never have a problem of tearing / stuttering. By default Doom 3 has 62 / 63 fps cap. Just for the "smoother" appearance, I cap it to 60 and have great looking gameplay with no uneven frame pacing or other anomalies. No matter the settings or whether I use RTSS or not - visual bugs are present always. So I assume it has to have something to do with the drivers, OS or the Doom 3's engine itself.

dhewm / dhewm3

Visual Bugs (on nvidia+Windows) #319