Bump map artefacts

[Igor_K]

hi Paul , All,
I have noticed sometimes I have artefacts on Bump map. See render below:

You can see (depending on camera angle) that there are some shading/lighting artefacts (edges marked with green).

If we compare to the Polysurface, you can see that artefacts appear directly along surface edges:

BTW, surface was created with TSplines for Rhino5. Is this the core of the problem, maybe??

So, why those artefacts appear?? Is it related in any way to "Shadow terminator" issue ?? or something else??

Attaching Rhino6 file:

surface_test.zip

(1.23 MiB) Downloaded 205 times

Thanks,
Igor

[face_off]

What version of the plugin are you using please?

Paul

[Igor_K]

Paul, I'm using Octane version: 2020.1.0.121 - Enterprise

[whersmy]

Might be a scene scale issue? Can you check the rayepsilon slider in Kernel?

[face_off]

I didn't get any artifacts when I rendered your scene. I could be a shadow from your environment map.

Paul

[Igor_K]

Might be a scene scale issue? Can you check the rayepsilon slider in Kernel?

I tried to adjsut Ray Epsilon slider - no effect on the result, still seeing artifacts.

I didn't get any artifacts when I rendered your scene. I could be a shadow from your environment map.

I've tried with multiple different HDRi . With some of them its less visible (but still present).

Any other guesses?

[whersmy]

Can you export an .orbx?

Maybe try a 32-bit image? With displacement it can make a difference.
Also the Uv`s are proper, right?

[Igor_K]

whersmy

orbx attached

surface_test.orbx

(5.04 MiB) Downloaded 217 times

I'm using tri-planar mapping here and Octane noise texture for bump.

[whersmy]

Looked it into it, and yes, it is weird. It becomes way better visible when using a really small scale noise texture. When using a larger scale (though probably not the user-case) it`s not visible.

I never really had this issue before

[Igor_K]

whersmy

Thanks for checking!

Paul, maybe you can share .orbx file with Octane dev team to investigate?? I still not entirely sure whether its Octane issue or geometry issue (like I mentioned, geometry created with tSplines for Rhino5 and its not very "clean" CAD surfacing, more like a " quick concept" quality), so maybe its issue of bad geometry. I just want to know whats casing the issue and how to avoid it in the future.

Thanks.