OTOY Forums

A. Windows 11 Pro 24H2
B. Nvidia RTX 4090
C. 256 GB
D. Nvidia driver version 572.60
E. OctaneRender Standalone version 2024.1.2
F. OctaneRender plugin version 2024.1.2
G. Host application version Cinema 4D 2025.1.3

Cinema 4D crashes when rendering in picture viewer, using motion blur and particle groups in Octane render tag.
Please open the attached file and start rendering in picture viewer.
On my system it crashes after a few frames.

I tested this file in 2024.1.2-[R4]-0103 plugin. It crashes also in Live Viewer as soon motion blur is enabled.

Best regards,
Denis

Has anyone been able to reproduce the described bug with this file?

I also tried rendering the particles with an X-Particle Generator instead of the Octane ObjectTag, but Cinema 4D always crashed, regardless of whether it was set as duplicate, instance, render instance or multi-instances.

The only solution at the moment for me is to render motion vector and depth passes in standard renderer...

Best regards,
Denis

Hi Denis,

it doesn't crash if you disable the "Use groups" checkbox in Octane Object tag: But I'm not sure that your scene is using the groups correctly.

ciao,
Beppe

Thanks Beppe,

but when I disable the "Use groups" checkbox, the distribution of the different particles becomes even.

I couldn't find a documentation to this checkbox and how to use it correctly. My assumtion was the order of the meshes is the order of the groups, because it works that way correctly with the distribution of the different particle sources.

When I use a generator for the particles in my original scene file it crashes the same way.

I tried to use a generator in this example scene, It doesn't crash, but the motion blur renders wrong.

Where can I find the documentation to the "use groups" checkbox?

Best regards,
Denis

Hi,
please have a look at this example with only one Sphere primitive to get both color and radius from Particles Groups: "Use groups" option is necessary if you have more than one emitter object and more than one particle group.

ciao,
Beppe

Thank you Beppe for your help with the workaround!

Unfortunately I need the particle ratio defined by the modifiers and the different meshes for the different particle groups. My entire setup consists of five emitters and ten particle groups.

In summary:
1. The X-Particle setup works perfectly and does what I intended.
2. The Octane ObjectTag renders the particle groups correctly.
3. Only the motion blur doesn't work when particle groups are used in the Octane ObjectTag.
4. Using xpGenerators in my setup renders with motion blur in the Live Viewer, but no particles are rendered at all in the Picture Viewer.

Any news from the Otoy team on this topic?

I've added a video of the entire setup. It's a grain sorting machine.

Best regards,
Denis

Ok, the issue is caused by xpChangeGroup objects, if you remove them and use groups in "normal" way, it doesn't crash with motion blur: ciao,
Beppe

Thanks Beppe,

I tried to create the different particle ratio with four emitters with different birth rates and seed instead of using modifiers that change the particle group.

But it crashes just the same.

Please have a look into the attached file.

Best regards,
Denis

Hi,
the "Use groups" support is quite limited, and your setup is something that plugin doesn't expect.

You have four emitters with one group each, but four objects assigned in Octane tag each.

Here is a setup that plugin is expecting: Only two Emitters, with two groups each, and two objects per Octane tag: ciao,
Beppe