poor image quality rendering

[s_gru]

i get poor image quality on 1st frame of a sequence i'm rendering (2 different ones actually) and i have to abort and restart the high quality render 4-6 times before it looks clean.

latest version of Vantage installed yesterday, video drivers on 2 4080 cards is: 546.01. i either get horizontal lines, or smooth walls are blotchy. the whole scene has daylight and many lights from 3ds max scene, but the animation is just 1 room/office. i have dynamic textures disabled (that seemed to help this morning, but not since) i'll attach my settings.

what i mean by abort and restart is that before the 1st frame is done, i abort the render and then render again. repeat, until it looks OK.

[s_gru]

here's some examples

[s_gru]

these lines are showing up also

[s_gru]

i just changed my render devices from 2 cards automatic, to 1 card. i had to re-start the live link but so far it's rendering a lot cleaner and of course double the time. i've just tried 1 card vs. 2 cards 3 times now, and each time i have automatic selected or, manually choose one or two cards, i get poor quality renders on 2 cards and better quality renders on 1 card only.

oh boy. now what.

[s_gru]

sorry - meant to post this in vantage forum.

[vladimir_krastev]

Hi, thanks for posting. Have you tried to enable the "legacy mode" of the Nvidia denoiser? This is done trough the render defaults menu.

[npg]

I don't think it's related to the denoiser. Such lines point to an issue with the multi-gpu render. The difference in quality is probably because Light Cache is not supported in multi-gpu mode.

[s_gru]

yes in fact i did try using legacy denoiser and that didn't help.

i can't grab a screen shot of what it looks like when the vantage viewport updates, but it initally starts with a ton of lines (maybe its in one of my examples?) with 2 GPU's. 1 GPU is a lot better.

also i do have Lightcache disabled (that was one of the first things i tried).

i am also seeing this reflection or highlight just below this linear light. and this is only with 1 GPU. so i'm investigating my materials and model and light to see if i can get rid of it. it moves right-to-left and starts out short, then grows, then shrinks back down. i have similar "flares" with can lights in the scene.



EDIT: my best results comes from using 1 GPU only. i saw some talk about a bug with using a video card connected to a monitor. i didn't notice if 1 of my cards was better than the other in my testing. i have two monitors hooked up to 1 card and the 2nd card is free.

[Marcus_C]

yes in fact i did try using legacy denoiser and that didn't help.

i can't grab a screen shot of what it looks like when the vantage viewport updates, but it initally starts with a ton of lines (maybe its in one of my examples?) with 2 GPU's. 1 GPU is a lot better.

also i do have Lightcache disabled (that was one of the first things i tried).

i am also seeing this reflection or highlight just below this linear light. and this is only with 1 GPU. so i'm investigating my materials and model and light to see if i can get rid of it. it moves right-to-left and starts out short, then grows, then shrinks back down. i have similar "flares" with can lights in the scene.



EDIT: my best results comes from using 1 GPU only. i saw some talk about a bug with using a video card connected to a monitor. i didn't notice if 1 of my cards was better than the other in my testing. i have two monitors hooked up to 1 card and the 2nd card is free.

Hi,

This has been an issue in previous versions as well, the horizontal "bars"/lines seems to be resolution dependent as they differ in height depending on resolution.
We get the lines with Vantage 2.2.1 & 2xGPU's and the Nvidia Optix denoiser(even when running in legacy mode), the lines don't appear evenly in images as the lines are weaker/non existent in areas with a highlight for example.

[npg]

I see an issue with a change we made in 2.2.2 that affects the computed screen space velocity in multi-GPU mode. This should affect motion blur and temporal denoisers. But you're saying this happened in 2.2.1 -- are you sure it wasn't a newer build?

[s_gru]

here's what i have.

[Marcus_C]

I see an issue with a change we made in 2.2.2 that affects the computed screen space velocity in multi-GPU mode. This should affect motion blur and temporal denoisers. But you're saying this happened in 2.2.1 -- are you sure it wasn't a newer build?

Hi, Yes I'm sure I double checked this and it's in 2.2.1. I also upgraded to 2.2.3 and it's the same issue, I get the horizontal lines there as well.

[s_gru]

so this is no light-cache, no moblur, 1 GPU. anyway to get rid of these? the vray light is in the can but a few inches. the can has a small ring around it which proud of the ceiling which has a normal map. or could this be related to the issues somehow? denoise is non-legacy nvidia. i showed previous image which affected the linear lights and those seem to be minimized now, but this has become a bit more prominent on the can lights.



i turned off bloom but that didn't help.

[npg]

We will investigate if you can share a scene here https://support.chaos.com/hc/en-us/requests/new (with link to this thread)

[s_gru]

what's funny about this, is it seems to get worse the more it renders up to the 500 samples i have specified. also, in the vantage viewport, it clears up after similar amount of passes and looks fine on each frame that i advance to. just during the animation sequence (saving out to jpg files) it progressively gets a little worse and stays there.

i've adjusted: lights tree samples, shading graph / shading graph for glossy/GI, disabled dynamic textures. so far no luck in getting rid of that. i have not tried using or disabling light cache, i keep that off. i'll try that next.