OTOY Forums

Octane does not support USD primitives set to invisible. Which is problematic because just deleting primitives in an animation does not properly work in solaris and results in issues with the motion blur node.
Please support visibility

HandcraftedMedia wrote:Octane does not support USD primitives set to invisible. Which is problematic because just deleting primitives in an animation does not properly work in solaris and results in issues with the motion blur node.
Please support visibility

Hi HandcraftedMedia,

Thank you again for reporting this issue.

Would you please share a sample scene to investigate?
You can PM me directly!

cheesrs

Sorry it took me a little while to get to putting together an example file.
This one illustrates both the "motion blur" getting stuck and the need for the solaris visibility setting. Please not that you will need MOPS installed for this file to make sense. https://github.com/toadstorm/MOPS If that's a problem I can make an example without it but this was the easiest for me.

In the file note two things:
1. As you scrub to the beginning of the scene while in the octane preview you will see that the animated elements don't disappear as they do in the object context, or if you have the motion blur node disabled. This same thing happens with Karma. It seems that the Motion blur node caches the scene. It seems to me that USD does not like objects just being removed in an animation and does not know how to deal with that when caching so it just leaves them at it's last location. The proper way to resolve this (which works fine in Karma) is to instead of deleting the elements instead to animate a "usdvisibility" attribute (https://www.sidefx.com/docs/houdini/sol ... mport.html see attributes). Alternatively animating the "usdactive" might also work. Unfortunately at this point octane does not support either of those and thus makes animating objects with motion blur that disappear impossible it seems to me.

2. If you scrub back and forth in the animation, even without the animation of elements disappearing (scrub in the later parts of the animation) - at least for me object tend to randomly get "stuck" meaning a duplicate from a previous frame will appear. Those go away if you restart the render.

Hope this is helpful. I do want to note that aside of some of those issues and missing features the octane implementation is surprisingly solid and I can't wait to implement it more in my workflow. Thank you for your work!

It seems like I am having a hard time attaching the file here so I uploaded it to gdrive for you:
https://drive.google.com/file/d/1Dr3vpx ... share_link

HandcraftedMedia wrote:Sorry it took me a little while to get to putting together an example file.
This one illustrates both the "motion blur" getting stuck and the need for the solaris visibility setting. Please not that you will need MOPS installed for this file to make sense. https://github.com/toadstorm/MOPS If that's a problem I can make an example without it but this was the easiest for me.

In the file note two things:
1. As you scrub to the beginning of the scene while in the octane preview you will see that the animated elements don't disappear as they do in the object context, or if you have the motion blur node disabled. This same thing happens with Karma. It seems that the Motion blur node caches the scene. It seems to me that USD does not like objects just being removed in an animation and does not know how to deal with that when caching so it just leaves them at it's last location. The proper way to resolve this (which works fine in Karma) is to instead of deleting the elements instead to animate a "usdvisibility" attribute (https://www.sidefx.com/docs/houdini/sol ... mport.html see attributes). Alternatively animating the "usdactive" might also work. Unfortunately at this point octane does not support either of those and thus makes animating objects with motion blur that disappear impossible it seems to me.

2. If you scrub back and forth in the animation, even without the animation of elements disappearing (scrub in the later parts of the animation) - at least for me object tend to randomly get "stuck" meaning a duplicate from a previous frame will appear. Those go away if you restart the render.

Hope this is helpful. I do want to note that aside of some of those issues and missing features the octane implementation is surprisingly solid and I can't wait to implement it more in my workflow. Thank you for your work!

Hi HandcrafMeida,

Thank you so much for the detailed info and your feedback!

It seems like the element disappearing may be related to scene translation.
The timeline scrubbing speed can be improved if we use a File cache node right above the Octane or Render Settings node.
Also, Octane does not seem to require the motionblur node as we already have the MB subsampling implemented internally.

The proper way to resolve this (which works fine in Karma) is to instead of deleting the elements instead to animate a "usdvisibility" attribute (https://www.sidefx.com/docs/houdini/sol ... mport.html see attributes). Alternatively animating the "usdactive" might also work. Unfortunately at this point octane does not support either of those and thus makes animating objects with motion blur that disappear impossible it seems to me.

We had a quick look at it, however, Solaris is setting the scene meshes to visible during final renders. It might be a Solaris bug or my scene is incorrect.
Would you please help share a sample scene on how Karma is working using the "usdvisibility" or "usdactive"?

cheers

I can provide a file for the USD visibility/ active.

On the motion blur side I was not able to get motion blur working without the motion blur node. Is there a setting I have to activate to get it working?

HandcraftedMedia wrote:I can provide a file for the USD visibility/ active.

On the motion blur side I was not able to get motion blur working without the motion blur node. Is there a setting I have to activate to get it working?

Hi HandcraftedMedia,

Yes please! ah true, we need the file cache to make the motion blur work with Octane. sorry about that!
Perhaps the velocity data is added when we bake as usd cache.
Once the nodes are cached the motion blur can be adjusted from the *Motion Blur Sampling* tab.

cheers