Object Sequence Crash & Motion Blur Problem

[jonjambon]

I've been testing out using fluid simulation mesh sequences from Houdini Apprentice and Realflow (a 30-day trail. I've yet to decide which to invest in for fluid sims) for LightWave 2020... In this case, I was able to use a mesh sequence from Houdini along with a second export of the same mesh sequence using the velocity attribute to create a mesh to use as a Morph Target in LightWave. With this I can achieve motion blur for the mesh sequence in LightWave... But, in regard to this, there seems to be a couple of bugs in relation to Octane.

The first bug is a crash that happens when I try to render using MultiPass Motion Blur. (I prefer this because it resolves Hot Pixels more quickly with less samples along with Neat Video for denoising) After the first pass on an F9 render, LightWave completely crashes and closes out... This is a very simple test scene with not too much memory usage. So I feel like this shouldn't be happening.

The second bug happens in another version of the same scene where I try to use Morph maps with a velocity morph for motion blur instead of a second mesh sequence as a Morph Target... In this version, Octane doesn't seem to recognize any motion blur at all. I have "Enable deformations MB" checked with just one MB pass. So, again, I feel like this shouldn't be happening... This scene also crashes with MultiPass Motion Blur.

I've attached both scenes along with the logs for crashes.

[juanjgon]

Hi,

The multi-pass motion blur is not compatible with the conventional native Octane motion blur. You need to disable the motion blur in the LightWave camera to use it.

Once disabled, you can render both scenes using the multi-pass motion blur technique without problems, and both have the motion blur effect.

Thanks,
-Juanjo

[juanjgon]

I've fixed this issue for the next build. The plugin will disable automatically the conventional motion blur if the multi-pass motion blur option is enabled.

Thanks,
-Juanjo

[jonjambon]

Oh, ok. I see now... Thanks.

So I suppose the other problem, with MultiPass turned off, of Object Sequences canceling out Morph deformation motion blur is another compatibility problem.

[juanjgon]

Nope, it seems that the morph deformation can't be evaluated by the plugin to get the motion blur, but I'm thinking that the plugin could use a "velocity" attribute itself to compute the motion blur without workarounds. Let me think about it ...

Thanks,
-Juanjo

[juanjgon]

Ok. Done! In the next plugin build you are going to be able to use the "velocity" attribute to compute the motion blur of any kind of object. Previously this feature was available only for the particles. You don't need any other workaround or morph configuration. As a bonus, the deformations motion blur from velocity attributes is also available in the IPR.

Thanks,
-Juanjo

[jonjambon]

That'll be good. Thanks.

This is starting to make me wonder about whether there's the possibility of loading Alembic sequences through the Octane plugin in a similar manner to how OpenVDB sequences are handled. Considering LightWave's Alembic Loader doesn't support mesh sequences... I'll post it in the User Requests.