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Hello

I see there are a few motion blur topics going currently but I promise this one is at least slightly different

Exporting scenes from Houdini to ORBX in order to render them on the RNDR network is becoming a concern of mine. Currently when I try to export scenes from Houdini to ORBX many objects that do have motion blur in the plugin's IPR do not have motion blur in standalone or when rendered on the RNDR network.

I've attached a simple example scene where a sphere is transformed along the X axis using a keyframed transform node. This appears correct when rendered in Houdini but not in Standalone or RNDR.



Additionally- not related to motion blur but ORBX from Houdini - ORBX come quite clean from other DCC with few extraneous nodes which is not the case coming from Houdini. If it were merely a visual distraction it would be tolerable to have so many extra nodes but there always seems to be between 6-40 render targets from even the simplest of scenes. Finding the correct render target and making sure to track that to submitting the job on RNDR to make sure the right target is selected for each scene is less than ideal. But maybe it's a feature and I'm simple and would like for everything to be like C4D ;P


Thank you for you time -

There is Motion Blur in your ORBX. It's just really weird. You have to crank Shutter Time to 1000 in order to see it. Something is definitely wrong when exporting to ORBX.
When you export the sphere to alembic and import it to Standalone, it works as intended.

Interesting - I see that now. Even in more complex scenes with fluids and changing point counts this works. Maybe something to do with scene scale?

james_conkle wrote:Interesting - I see that now. Even in more complex scenes with fluids and changing point counts this works. Maybe something to do with scene scale?

I don't think it has anything to do with the scene scale but maybe Juanjo knows better. If you compute velocity attribute on the sphere, you'll see that v.x goes from 0 to ~5. If you unpack the ORBX and import that alembic back into houdini, you'll see that v.x goes from ~0.0006 to ~0.2. Seems that something is wrong with the export.

I also went and animated the camera along the Y-axis and when the camera is animated - turning the Shutter Time to 1,000% doesn't work as a fix as the camera motion blur goes crazy.

I've attached the hip and orbx below.

Hmm, Ok. I'll take a look at these issues ASAP. It is something weird because the .orbx is exported from the same data that is rendered inside Houdini.

-Juanjo

I'm having the same issue as James - but I also can not do this because the camera is moving a bit. In my case it's motionblur generated by trails of objects scattered on points which are moving. I can't share the scene unfortunately as it is under NDA. But I'm guessing the root cause is the same. In Houdini the motionblur works like a charm.

Best regards,

Until its fixed, if you need to send the scene to RNDR, i would suggest that you export everything as alembic and assemble the scene in Standalone instead of exporting as ORBX.

Any ETA on when this could be fixed? It's fairly essential for almost anything to have proper motionblur.

Otherwise I'm extremely happy with the ORBX exporter in Houdini. This is really the one thing I'm desparately needing as there is little control in standalone over object motionblur.

Best regards,

Sorry, I'm still investigating this issue. Really I can't understand why the .orbx files don't have the same motion blur settings that you get while rendering the scene inside Houdini. I think that the problem can be on the Octane side, but I need to isolate some repro cases to let the core team investigate them. I hope to know more about it soon.

Thanks for your patience,
-Juanjo