5 to 10 percent of rendered exr's missing scanlines

Hello nvidia,

for several tries now, 5 to 10 percent of the image I render through movie capture come out missing scanlines ( causing other tools to flag them as “incomplete”. I am rendering a 2500 frame sequence with about 7 AOV’s each. They are all stored as separate exr’s written to a local ssd drive.

Is this a known issue? Is there something I can do to prevent this?

Thanks,
Koen

That is very strange. I have not seen that before. Are you running low of GPU memory? It is always the same frames? What happens if you try to render without the AOVs? Is it a very heavy scene? You could try deleting the damaged frames and then re-render the frames using Movie Capture again, but making sure “Overwrite frames” is OFF. This will skip through the animation and only render the missing frames.

In general, make sure you have enough GPU and CPU ram to render. Do not use your computer and let it render. Do not let it go to sleep. Do not switch applications.

thanks for the tips. it’s a pretty heavy scene and normally I render on an a5000, but since the dual gpu’s broke, I am now rendering on a 4090.
It’s not always the same frames. Rv shows the image with the missing scanlines. those are not consistent either. I can try to run a small batch without aov’s tomorrow. I’ll write a script to delete the bad frames and then run again, hopefully that speeds things up.

I have rendered heavier scenes on that 4090, up to 10k frames with all the aov’s a few months ago ( earlier version of composer, probably older gpu drivers ) and several batches of 10k frames had none of these issues.

If I find out more, I’ll update here. Thanks

The only time I have heard of this happening was in a scene that had bad animation data at certain keyframes and it causes the RTX renderer to “stutter”. It just a flythrough of a static scene or is there animated objects in the scene?

only the camera is moving. The broken images will have maybe 20 black lines not always in the same spot. It’s really odd. I can send some images over email if that would help.

Thanks,
Koen

rendering just the beauty, without aov’s ( so not using a render product ) makes the problem go away. Tomorrow, I’ll try to reduce the nr of aov’s to a minimum and see what happens.

I rendered a full sequence without render product and things worked fine. I then limited the aov’s to the minimum ones I need and got the issues again. These are the aov’s I turned on.

I am seeing some warnings about dlss when I turn them on, but I would assume this only affects the specific aov?

koen

my last try game me the least complete image I have seen yet, enough is covered I can share it here :

The only thing I can think of is that the high resolution frame plus all of the AOV is slightly too much memory to push through the card so quickly.

Maybe just find a happy medium and find out exactly where it starts to fail with so many AOV’s

I think something broke recently unfortunately, it was working fine 6 months ago on much heavier scenes. Not a lot I can do with omniverse at the moment, one machine dead in the water because of a dual gpu issue and the other one cant write exr’s properly. Hopefully a future release will solve both.

Thanks for the help so far

Hello Richard,

I think perhaps good news, changing the compression type on the exr files seems to avoid this issue ( using dwa now ) .

Wow good find !! We will get it fixed !!

sorry, I celebrated to soon. I still got some, although a lot less. I feel there is some congestion in the exr writing that breaks. I might try to set up the farm software so I can distribute, but fir now I’m switching to cycles to get these renders out.

Thanks for all the help!

Oh no ! I will investigate