question

Jakob Appleby avatar image
Jakob Appleby asked ·

"degenerate polygon objects found in frame: x" error from alembic file

Hey i have this problem with an Alembic file from Houdini.

Its a debris sim with quite a lot of objects, but all from 8 instances. For some reason i only get to render the first frame they exist, then on the later frames i get "degenerate polygon objects found in frame: x" in the console

C4D viewport and a normal render can see all the debris, all frames.

alembic
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Jakob Appleby avatar image
Jakob Appleby answered ·

Hey, fixed it! Using a clean node in Houdini lets me delete "NANs"

Made them show up each frame now

Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Jakob Appleby avatar image
Jakob Appleby answered ·

Yeah the Procedural object renders it too

1 comment Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Thanks for the confirmation.

0 Likes 0 · ·
Peter Horvath avatar image
Peter Horvath answered ·

Glad to hear you could fix it. Could you please check if the alembic Arnold Procedural object can read and render the fixed file? Or if you can send me the fixed file, I can check myself.

Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Peter Horvath avatar image
Peter Horvath answered ·

Yes, using the native importer I see the objects in the viewport and in the Standard/Physical render. As the warning says, there are some invalid values in the vertex list coming from the Alembic file. Maybe it's something wrong with the sim?

2 comments Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Alright, ill see if there is anything i can do to make it work on the output in houdini.

0 Likes 0 · ·

Im at a loss here, cant seem to find any parameter that affects this at all, be it packed objects or not. Might be something that comes from the instancing of the different types of debris onto points in houdini. Need to find a workaround for that to even test it

0 Likes 0 · ·
Jakob Appleby avatar image
Jakob Appleby answered ·

But you see them in viewport at frame 12 at z -600 ish? And you can render them with physical render?

I wonder whats up with that.

Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Peter Horvath avatar image
Peter Horvath answered ·

This alembic file is not rendering for me at all and if I move to frame 10+, then I've got a different warning:

C4DtoA | 00:00:53   697MB  WARNING|   resetting parameter vlist on /RBD_Main_sim/Debris_sim_Out_4 (found: nans or infs)

The native loader has no problem with it, so something's definitely not right in the Arnold alembic procedural.

Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Jakob Appleby avatar image
Jakob Appleby answered ·

Bit too big to upload here but you should be able to grab it here:

https://www.dropbox.com/s/5zpis1us9ke1k8a/debris_cachedsim_fewerframes.abc?dl=0

Its 24 fps, things start spawning at frame 12, and all other frames fail to render them, even IPR.

(It doesn't spawn near the axis)

Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Jakob Appleby avatar image
Jakob Appleby answered ·

Yes ill see what i can do, right now its too big to send.

Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Peter Horvath avatar image
Peter Horvath answered ·

Can you send me the Alembic file or just a simple one with the same issue?

Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Write an Answer

Hint: Notify or tag a user in this post by typing @username.

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Welcome to the Arnold Answers community.

This is the place for Arnold renderer users everywhere to ask and answer rendering questions, and share knowledge about using Arnold, Arnold plugins, workflows and developing tools with Arnold.

If you are a new user to Arnold Answers, please first check out our FAQ and User Guide for more information.

When posting questions, please be sure to select the appropriate Space for your Arnold plugin and include the plugin version you are using.

Please include images, scene and log files whenever possible as this helps the community answer your questions.

Instructions for generating full verbosity log files are available for MtoA, MaxtoA, C4DtoA, HtoA, KtoA, and Kick.

If you are looking for Arnold Documentation and Support please visit the Arnold Support site.

To try Arnold please visit the Arnold Trial page.

Bottom No panel present for this section.