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Motion Blur for Fluids Simulations?

Posted: Tue Oct 23, 2018 7:26 pm
by brent_3d
Is there a direct way to create motion blur for fluid simulations in Blender\Octane v3 ???

Re: Motion Blur for Fluids Simulations?

Posted: Tue Oct 23, 2018 7:52 pm
by grimm
You should be able to, just make sure to set the fluid's geometry type to "movable proxy" or "reshapable proxy" so Octane knows to do the object motion blur. I haven't tested this yet, so YMMV. :D

Re: Motion Blur for Fluids Simulations?

Posted: Wed Oct 24, 2018 1:46 am
by brent_3d
grimm wrote:You should be able to, just make sure to set the fluid's geometry type to "movable proxy" or "reshapable proxy" so Octane knows to do the object motion blur. I haven't tested this yet, so YMMV. :D
Tried it but still can't seem to get it to work. Anyone else got this to work?

Re: Motion Blur for Fluids Simulations?

Posted: Wed Oct 24, 2018 10:18 am
by J.C
Tried in V4 but got an error with reshapable mesh and Internal motion blur. It just don't render (some error).

Re: Motion Blur for Fluids Simulations?

Posted: Wed Oct 24, 2018 6:54 pm
by brent_3d
J.C wrote:Tried in V4 but got an error with reshapable mesh and Internal motion blur. It just don't render (some error).
Anybody out there got the the Motion Blur to work with Blender's Fluid Sim in v3 or v4? At this point Octanes Motion Blur or Blender's Vector Blur will do, but I've tried all I can think of so if someone has the solution chime in please.

Re: Motion Blur for Fluids Simulations?

Posted: Thu Oct 25, 2018 5:50 am
by grimm
I spent some time looking at this but wasn't able to get it to work. I think I know what the problem is though. When I was testing I also put a rigid body sphere in the scene as well so I could see if I could get it to do motion blur as well. This is the interesting part of this. I ran the simulation for the fluid and then ran the simulation for the sphere, but I did this before I assigned the sphere object's geometry type. Then I set the geometry type to "movable proxy" and rendered one of the frames. Both the fluid and the sphere had no motion blur. So I re-ran the simulation of the sphere and all of sudden the motion blur for it started working. It's definitely an order of operations thing. So I set the geometry type to the fluid objects to "moveable proxy" and re-ran the fluid simulation, but it didn't work. I think that there is something missing with the fluid simulation and the fluid objects don't get the flag set for motion blur. I suspect it's because the fluid objects are generated from other objects and the plugin doesn't see those objects as having the correct geometry type.

Here is what the render looks like:
mb-fluid-test.png
I exported a orbx file so I could see if motion blur would work in stand alone, but that didn't work out very well either. :( Instead of the object moving it just brought each frame in as another object.
mb-fluid-test1.png
Looks like a bug to me.

Re: Motion Blur for Fluids Simulations?

Posted: Thu Oct 25, 2018 6:45 am
by brent_3d
Thanks for the testing Grimm, Lino showed me that the the Flip Fluids Addon works with the Octane/Blender Motion Blur so I'll be using that shortly plus it's awesome anyway.

Re: Motion Blur for Fluids Simulations?

Posted: Thu Oct 25, 2018 7:07 am
by grimm
I would be very interested in that as well, I generated the fluids with Flip Fluids as well, but I couldn't get it to work.

Re: Motion Blur for Fluids Simulations?

Posted: Thu Oct 25, 2018 3:15 pm
by pegot
brent_3d wrote:Thanks for the testing Grimm, Lino showed me that the the Flip Fluids Addon works with the Octane/Blender Motion Blur so I'll be using that shortly plus it's awesome anyway.
If you start working with Flip Fluids be aware of some issues I found with it and Octane Blender: any setting you make in Octane Properties pane will be reset during rendering so you can not use camera visibility or Octane subdivision (it might effect the Mesh type as well, though I haven't tested that). See my post below:

viewtopic.php?f=114&t=68738

Re: Motion Blur for Fluids Simulations?

Posted: Thu Oct 25, 2018 5:21 pm
by brent_3d
pegot wrote:
brent_3d wrote:Thanks for the testing Grimm, Lino showed me that the the Flip Fluids Addon works with the Octane/Blender Motion Blur so I'll be using that shortly plus it's awesome anyway.
If you start working with Flip Fluids be aware of some issues I found with it and Octane Blender: any setting you make in Octane Properties pane will be reset during rendering so you can not use camera visibility or Octane subdivision (it might effect the Mesh type as well, though I haven't tested that). See my post below:

viewtopic.php?f=114&t=68738
Thanks for the heads up!