Arnold is not rendering multi-instances in certain situations

[Daniel_Hildebrand]

In certain situations, typically involving nested instances and a cloner at the top of the hierarchy set to multi-instance, Arnold will not render the instances. If I set the top cloner mode to just "instance", it works, but im setting up a scene which will end up having hundreds of instances, and theoretically multi-instances should help a ton here. Not sure if im missing something, or if it's a bug or limitation? The same exact setup in Redshift works just fine.

Thanks!

Cinema 4D S22.123, Windows 10

C4DtoA 3.3.7 [aba61815]

Arnold core 6.2.1.1

Arnold

Redshift

[Stephen.Blair]

It would be great if you could post a repro scene (or send it to support at arnoldrenderer dot com)

[Daniel_Hildebrand]

@ Stephen Blair

I couldn't attach the file to this post for some reason, but here's a simple repro scene. (Dropbox url).

https://www.dropbox.com/s/5up1iw11z5zjx5q/instancing_troubleshoot_01.c4d?dl=0

There's two setups in the scene to demonstrate. Both cloners are set to multi-instance.

"01" has the instances referencing a hierarchy of objects. The objects display correctly in the viewport, but are incorrectly displayed in the IPR.

"02" the instances reference just the one object. This works correctly in both viewport and IPR.

So the issue seems to be related to the instances referencing a hierarchy when the cloner is set to multi-instance.

[Stephen.Blair]

Thanks Daniel

To attach a scene, you'd probably have to rename it to a .txt file

[Daniel_Hildebrand]

I tried to rename it to a .txt (on windows) but it retains its .c4d file type association and still wont wont let me post it here 😞

Were you able to grab the file from my dropbox link? If there's a better way to submit the scene let me know.

Hopefully there's a solution for the multi-instance issue. Thanks!

[Stephen.Blair]

Hi Daniel

Yes, I got the file.

On Windows, by default it hides the file extensions, so you end up with a file named instancing_troubleshoot_01.txt.c4d
I disable that option:

instancing_troubleshoot_01.txt

[peter.horvath6V6K3]

Thanks for the scene Daniel, I will check the file once I have chance. Will keep you updated.

[Daniel_Hildebrand]

Ahh thank you for that tip. I could have sworn earlier versions of windows allowed this.

Looks like attachments work now!

instancing_troubleshoot_01.txt

[Daniel_Hildebrand]

Thanks appreciate it!

[peter.horvath6V6K3]

It's a bug in the plugin, the transform of the multi-instances is not set correctly. Basically the transform of the intermediate Instance Object is ignored. Working on a fix.

[Daniel_Hildebrand]

Great to hear. Thanks for looking into this, really appreciate it!

[peter.horvath6V6K3]

I've got a potential fix. I you would like to test it, please send an email to support(at)arnoldrenderer(dot)com and I can send you a custom build.