cleaning process in slow motion

[Jassir]

Is it impossible to animate the time scale parameter or does this only apply to the FLIP solver?
Could I use it with Classical Advection mode or would I run into the same problem that I had before?

[Svetlin.Nikolov]

Hi, so when you roll back to classic advection you just need just the time controls on the input panel, there won't be any resimulation involved. Try the 'interpolate' or 'blend' methods and see which one works better for you.

Also, I'm curious about the particle ID warning - it really shouldn't appear if you don't use the FLIP solver and especially if you use the classic method with no foam or splash. Do you have only one simulator in the scene, or there are many?

[Jassir]

I started a new test scene and I think the fact that the error showed up using classic was my fault. I set up the dynamics before setting up the liquid controls. Now I realized that when i enable liquid, the FLIP solver is activated automatically as well. So I think I worked with the FLIP solver accidentally.

But it definitely happens with the FLIP solver.

[Svetlin.Nikolov]

Yes indeed, activating Liquids in the latest nightly builds automatically enables the FLIP solver and several other options, which can mess with the settings you have already adjusted. We will split the fire and liquids simulators soon, so that such automatic changes in options will not happen.

[Jassir]

Hello,

after trying the classic method I decided to go back to the FLIP advection. This way I have more details and a better water behavior. I know that I can't interpolate anymore but I think I can get close to the desired effect with an frozen frame via (Direct Frame) and a camera rotation.

Now I have some problems with the Motion Blur of the water mesh. When I freeze the water I want only little motion blur. During the rest of the animation the motion blur has to be a lot stronger.
Therefore I could not use the camerasettings in the rendertab (wasen't able to animate them), instead I used a Vray physical cam with no exposure and a shutter-speed of 1/100 (more motion blur) and 1/2000 (less motion blur).
The thing is that my motion blur looks good if I use implicit surface mode. But it is always the same amount.
If I use "mesh" as surface render mode the amount of motion blur changes but the motion blur looks bad (darker, strange triangle like artifacts).

Here is a screenshot to illustrate my problem (shutterspeed 1/100)


I tried to increase the samples in the object properties of the Phoenix object. But that did not help.

I would rather use implicit surface method if there is any way to change the amount of motion blur there.

Another thing I realized is the behavior of the water drops on the right. They seem to "float" above the surface. Is that due to the high velocity or the small size? Is there something I can do about that?

[Svetlin.Nikolov]

In implicit mode, try to animate the velocity multiplier of Phoenix under the Rendering panel - this will work as a direct MB multiplier.

I could not reproduce the floating droplets though, are you using the default "Inscribed" voxel mode under the Interaction panel?

[Jassir]

Thanks so much for the tip with the Velocity multiplier, that's exactly what I was hoping for.

And yes I do use the "Inscribed" voxel mode.

[Svetlin.Nikolov]

It looks like a collision issue with the FLIP solver, you could either try to move a mesh up or down and hope for the best, or use a separate mesh for rendering, until the issue is resolved.

[Jassir]

I think I will ignore it for now

[Jassir]

Thanks for all your help so far. I will just keep asking if that is ok.

The waterjet I simulated is supposed to clean an object. I thought I could distribute some particles over the objects using particle flow, add the "Phoenix FD force" operator and be done.
Unfortunately I used inertial forces and animated the Phoenix Grid. The result is that the particles move with the grid. Like they are linked to it. Which would make sense if I had't used inertial forces.
Is there some setting or workaround to counteract this effect?

[Svetlin.Nikolov]

Very strange, there was an issue with the particle force and inertial forces several months ago, and it was fixed. Is it possible to attach your scene or email it to the support team?

[Jassir]

Sure here is the scene:
testscene_particle.zip

[Svetlin.Nikolov]

Yes, there definitely is a problem with the inertial forces, stay tuned for the fix or a workaround.

[Jassir]

Ì will. Thanks a lot for your help.

[Jassir]

Hi there, did you have time to take a closer look at this problem? Or should I think about a workaround?