weird bump with nvidia denoiser.

Corona Corona for 3ds Max Issues
1

max 2018.4
corona dailybuild 2019-05-22

i got a weird bump with nvidia denoiser, some areas looks blurry.

  • it happens with coronaBitmap and max bitmap, but not with procedural maps.
  • add bumpConverter helps a bit. but still looks incorrect.
  • IR without denoiser works at it should.
    check attached files.

by the way i remember someone here did post similar thing with white cloth object but i cant find the thread.

test - no denoiser - bump (coronaBitmap only) - 300 passes.jpg
test - no denoiser - bump (coronaBitmap only) - 300 passes.jpg640×480 78.1 KB

test - no denoiser - bump (max procedural).jpg
test - no denoiser - bump (max procedural).jpg640×480 56.3 KB

test - nvidia AI - bump (coronaBitmap only) - 300 passes.jpg
test - nvidia AI - bump (coronaBitmap only) - 300 passes.jpg640×480 43.5 KB

test - nvidia AI - bump (coronaBitmap w bumpConverter) - 300 passes.jpg
test - nvidia AI - bump (coronaBitmap w bumpConverter) - 300 passes.jpg640×480 69.6 KB

test - nvidia AI - bump (maxBitmap only) - 300 passes.jpg
test - nvidia AI - bump (maxBitmap only) - 300 passes.jpg640×480 52.3 KB

test - nvidiaAI - bump (max procedural).jpg
test - nvidiaAI - bump (max procedural).jpg640×480 54.2 KB

2

I would guess it’s expected with the AI denoisers, since they “hallucinate” detail where there think there should be some and make guesses as to what should be shown in places. Rather than just work with what is in the image already, they try to add and change things (one of the reasons why we don’t recommend them as final denoisers, at least not until there are significant passes so they need to make less “guesses” as to what the image should be).

3

hi Tom, how are you doing :smiley:
tested it with 300 passes where it works good on computing other features but fail on bump unfortunately. imho it should just gives less details instead of distorts the bump map with added blurriness.

4

Have you tried the same thing with another renderer using Optix? (e.g. V-Ray)
I am guessing that this is not related to how Corona works, but to how Optix works. We can of course investigate and check if we could improve this somehow, but also there is a new version of Optix coming to Corona soon (can’t tell exactly when), which might improve this.

5

Thanks maru, but unfortunately i have no vray.