Image filter stops working at a certain resolution.

[ronyx69]

These images are crops from renders with the same settings, one of them is slightly higher resolution. The filter (no matter which one I choose) stops working at a certain resolution, which is different for every scene. Simpler scenes can get higher resolution before the filter stops working.

This is a problem because the filter produces nicer images by making noise more natural and smoothing high contrast areas and sharp highlights, this can't be done in post. I can't use it for 5K resolution images.

Left is 3150x1772, right is 3100x1744, exact same settings. Tested on 3.30.04 and 3.30.05. I have not found anybody ever mentioning this problem anywhere. Tried remaking different scenes 3 times and resetting the settings, no luck.



Would be nice to know why this happens, and if anything can be done to fix it.

[vlado]

Are you using the progressive sampler? If yes, then this is normal; if the RAM required for sharing pixel samples for AA becomes too large, V-Ray will switch to per-pixel filtering instead. The end result is the same, but the way to get there is different.

If this is what happens, you should see some thing like this in the V-Ray log file: "Estimated progressive buffer memory usage of XXX MB is over the limit of YYY MB. Falling back to per-pixel filtering." You can control the limit using the environment variable VRAY_MAX_PROGRESSIVE_BUFFER; the default is 2048 MB.

Best regards,
Vlado

[ronyx69]

Yes, thank you! Didn't expect this to have such a quick and easy solution.

Why is the limit there and why is it so low in the first place? I set it to 12GB, could I run into any problems regarding this, can I keep increasing it? I have 16GB of RAM.

[vlado]

Well, the sharing of samples requires quite a bit of additional storage, especially if you use render elements, and it can quickly fill up all the RAM for large resolution images. So we needed some solution beyond "get more RAM" Whether the default is low, maybe, but with people having quite heavy scenes nowadays, we were not sure they would be pleased if all the RAM was used just for that feature.

Best regards,
Vlado

[allemyr]

Are you using the progressive sampler? If yes, then this is normal; if the RAM required for sharing pixel samples for AA becomes too large, V-Ray will switch to per-pixel filtering instead. The end result is the same, but the way to get there is different.

If this is what happens, you should see some thing like this in the V-Ray log file: "Estimated progressive buffer memory usage of XXX MB is over the limit of YYY MB. Falling back to per-pixel filtering." You can control the limit using the environment variable VRAY_MAX_PROGRESSIVE_BUFFER; the default is 2048 MB.

Best regards,
Vlado

Hi Chaosgroup,

Have one question, about per-pixel filtering and standard AA, is standard AA using GPU or processor RAM when doing a rendering with GPU? If it's using VRAM I'am fine with per-pixel filtering. If processor RAM I would like to try changing the buffer with the enviroment variable!

Where can I find the enviroment variable?

I read here but didn't get it:

https://docs.chaosgroup.com/display/...ment+Variables

Have 128gb processor ram and only 12gb vram.

Best!

[vlado]

When rendering on the GPU, we always use per-pixel filtering; no additional RAM or VRAM is used.

Best regards,
Vlado

[allemyr]

When rendering on the GPU, we always use per-pixel filtering; no additional RAM or VRAM is used.

Best regards,
Vlado

Ohh, I understand. Thanks!