Getting seams when doing N-sim with Mental Ray

[Mr.Blank]

I am getting seams when using mental ray for rendering a N-simulation (Autvolume is checked). When I switch to Scanline no seams appear and all transitions are smooth (including Multiple Scattering)

Is there a known issue with N-Sims and Mental Ray?

Edit: I also have problems with Mental Ray only rendering one of the FumeFX grids present in the N-sim scene. If I hide the grid that renders out, the other grid is rendered. When I un-hide the grid again, only one grid renders out.
Again when I switch to Scanline all grids renders out fine...

I am using
FumeFX 3.5.5
3D max 2014 SP5
Windows 7 -64
Ram 32 GB
CPU: 20 Cores

[sitnisati]

Hello,

Thank you for the bug report.
We will see if we can reproduce this error and let you know.

Best regards,
Kresimir Tkalcec

[sitnisati]

Hello,

Can you please post a simple scene as we cannot reproduce it here?

Thank you.

Regards,
Kresimir Tkalcec

[Mr.Blank]

Hi,
Here's a small test scene for N-sim.

I've also attached a test scene called Channel Data since I am not able to render Channel Data with Mental Ray. In the scene I am rendering Temperature. Works fine with Scanline but nothing shows up with Mental Ray. Great if you can have a look at this as well

I'll post example renders for both N-Sim issue and Channel Data issue.

Kind Regards
Thor

[Mr.Blank]

Here's the renders for the N-Sim scene.
As you can see there's seams and banding in the Mental Ray render but the same frame (39) looks fine in the Scanline render.

[Mr.Blank]

And here's the Channel Data renders.
Mental Ray shows nothing while Scanline works fine for the exact same frame.

[sitnisati]

Hello,

Cast/Receive MS option located under FumeFX' Illumination parameters is not suprorted in mental ray as well as Channel shader.
I apologize for not mentioning this in the help file - we will change this in the docs.

Thank you.

Regards,
Kresimir Tkalcec

[Mr.Blank]

Ok, but I also get seams when not using the cast/receive MS option with Mental Ray. Again it looks fine with Scanline. See attached renders.

Is the cast/receive MS issue also true for Vray?

Kind regards
Thor.

[sitnisati]

Hello,

This is to some extent covered inside the FumeFX help file, topic Mental ray issues.
When rendering with mental ray, you must never have FumeFX grids or geometry that are perfectly aligned with FumeFX grid.
Make the Master grid larger a bit, resim and it will render okay.

Regards,
Kresimir Tkalcec

[Mr.Blank]

Ah, ok.
Thanks for the help

Kind regards
Thor

[sitnisati]

Your're welcome!

Regards,
Kresimir Tkalcec