Sample Rate Cut

[sabine_vandertolschulz]

Can some one explain this to me?
There is a strange “cut” in the sample rate on the left hand side of the model that I can’t explain for the life of me.
I cant share the scene (company policy), sorry.
It’s not the adaptive dome, or the shading rate, or the lights.
When I use an override material, it’s gone. So it might be the material or maybe the camera.

Has anyone ever eoncoutered something like this?

Thanks in advance
Matei

[nikoleta.garkova]

Hi Matei,

It probably is due to the map used - maybe some reflection that behaves differently on that spot. Do you get this cut in the Beauty pass? What happens if you, for example, increase the Noise Threshold?

[kosso_olli]

Can you please to try set the Cutoff value under “Options” for that material to 0?
There have been similar errors in the past. Also, the noise, smoke and cellular textures shipping with Max are known to produce artifacts when set to very small scale.

[kosso_olli]

You might try the OSL procedurals (“Uber-Noise”) shipping with newer versions of Max 2021, or try the BerconNoise plugin. These should not create any artifacts.

[_Lele]

Max’s noises have terrible filtering.
A suggestion would be to use the VrayPluginNodeTex, picking “TexSmoke” in Max compatibility mode.
That is properly filtered (meaning that at the same size of the one you are using, the noise will likely disappear. But it’s there!), so you may need to play with bump amounts and sizes, but the rendertime sampling will be quite a lot better.

Attached, on the left, max’s own smoke (see the horrible filtering, which causes confusion to the sampler.), to the right, V-Ray’s version (Same parameters. they are both put into a color2bump to ensure the noise is nicely visible in the bump, at the cost of some speed.).

[sabine_vandertolschulz]

@kosso_olli

You might try the OSL procedurals (“Uber-Noise”) shipping with newer versions of Max 2021, or try the BerconNoise plugin. These should not create any artifacts.

Not allowed to update to Max 21 yet and don’t have Bercon but thanks for the tipp.

[sabine_vandertolschulz]

@_Lele

Max’s noises have terrible filtering.
A suggestion would be to use the VrayPluginNodeTex, picking “TexSmoke” in Max compatibility mode.
That is properly filtered (meaning that at the same size of the one you are using, the noise will likely disappear. But it’s there!), so you may need to play with bump amounts and sizes, but the rendertime sampling will be quite a lot better.

Attached, on the left, max’s own smoke (see the horrible filtering, which causes confusion to the sampler.), to the right, V-Ray’s version (Same parameters. they are both put into a color2bump to ensure the noise is nicely visible in the bump, at the cost of some speed.).

S**t yeah! That’s it!
I completely forgot about the PluginNodeTex. Set it to Speckle instead of Smoke and got it even more like the real thing.
Thank you so much!

Thank you all so much.

PS. my original smoke map had tiling under 1.0, that was exacerbating the artefacts the most.