Item masks and Instances

[Longbongosolo]

I'm trying to use a texturing method that I've used previously with Modo and V-Ray but it's crashing Octane.

I have a parent mesh item with a material and then instances of that mesh item. In the material group I use item masked sub-groups to give different textures to the parent mesh item and the instances. Can this work in Octane? Or is there a different approach I might try?

In the attached image you can see that the "1", "2" and "3" are texture maps targeting specific items. If I launch Octane with this setup, Modo just crashes.

[Hesekiel2517]

I think there is a different approach in octane: All the instances have a particle id. In the material you can access these particle id with a particle id texture (i hope thats the right name) and use this to mask your textures.

[funk]

While this shader tree setup won't work in Octane, it shouldn't be crashing. Can you share a scene where you're seeing a crash? It's not crashing here.

Octane requires a different approach, which is a bit more complicated. I have attached a sample scene.

You need to give each instance a unique value in Modo Item > Channels > Particle ID. My example has the parent mesh set to 0.0, cube (2) = 1.0, cube (3) = 2.0

You can then use an "Octane Instance Range" node as a mask, plugged into a gradient, which you feed your textures into.

[Longbongosolo]

Thanks Hesekiel2517 and funk, I suspected I should be using the ID approach but didn't really know how to do it so thanks for the explanation and scene.

I wasn't confident that the item mask approach was possible but thought I'd give it a go just in case. I guess there's gonna be a lot of ex-vray people getting used to working in Octane

I've attached my test scene if you wanna see if it crashes.

Thanks,
Will

[face_off]

Thanks Hesekiel2517 and funk, I suspected I should be using the ID approach but didn't really know how to do it so thanks for the explanation and scene.

I wasn't confident that the item mask approach was possible but thought I'd give it a go just in case. I guess there's gonna be a lot of ex-vray people getting used to working in Octane

I've attached my test scene if you wanna see if it crashes.

Thanks,
Will

Hi. That scene is not crashing for me. What version of Modo and the plugin do you have installed please? Have you tried deleting your MODO*.CFG file?

Thanks

Paul

[Longbongosolo]

Hi Paul, I am using Modo 15.2.2, Win 10. Octane version was 2021.1.1.180. Tried deleting the config and it still crashed. I updated to 21021.1.1.181 and it also still crashed. I also asked a colleague to try it and it crashed for him too.

[face_off]

Hi Paul, I am using Modo 15.2.2, Win 10. Octane version was 2021.1.1.180. Tried deleting the config and it still crashed. I updated to 21021.1.1.181 and it also still crashed. I also asked a colleague to try it and it crashed for him too.

There was no 2021.1.1.180 release. Are you able to check for the correct release number please?

Thanks

Paul

[Longbongosolo]

Sorry Paul, it was 2021.1.0.180

[face_off]

Thanks - it would be worth trying the latest release, as it is not crashing for me.

Paul

[funk]

Im using 2021.1.1.181 + modo 15.2v2 and Longbongosolo's scene crashes here too

EDIT: also crashes in 14.2v2 + 2021.1.0.180

EDIT 2: The scene is crashing due to the "Label" items. These are text polygons and the plugin crashes trying to render them.
The workaround is to freeze text polygons, or add a freeze meshop.