Help with volume retime issues.

[eunchae]

Hello.

I'm making an explosion.

It is an explosion that enters a plate shot at high speed.

I am wondering how to approach it..

Is it necessary to retime after adjusting the time scale slowly from the beginning of simulation work?

And there is a problem that can't be solved, such as flickering or interruption in the volume when retime is performed.

Does anyone have any advice on this?

Thank you.

[eunchae]

I solved the retime problem by simulating a 24FPS operation to 96FPS and then turning it back to 24FPS. But I don't think this is a perfect solution...

1. When there is only density, if I use the retime node, the feeling that the quality has decreased every frame repeats.

2. When there is a field other than density. In the case of an explosion, the fire will flicker.

Is there anybody to help?

Thank you.

[Keithtron]

The only volumes I've retimed have been dust, so no extra fields besides density/vel.  In the case of dust, I've been pretty happy with the Retime SOP.  Are you using the 'Advected' Blend Mode setting?

Sometimes with shots that bounce between hyper slow-mo and faster motion it's easier to just run the sim at slow motion, and then speed it up after.  You need to sim many more frames, of course, but likely a better end result IMO.  And as for speeding it back up, you could try the Retime SOP or something, but I've also seen entire shots/sequences rendered in slow mo and then time-warped in comp, even though it's really wasteful from a rendering standpoint.