substep sim data

[haggi]

Hi,

I have a flip fluid simulation which works quite nicely. Now I want to do a bit slowmotion. I tried autoDop time scale what works quite fine, but with smaller scale, the simulation tends to be a bit unstable. So my idea was to simulate with substeps and write the substep data to a sim file with $SF as file numbering. Unfortunatly all sim data will be written what is quite expensive because I have a high detailed collision object. So my question is: I'd like to write only my simulated particles to a sim file, how can I remove all other elements before writing the file?

[lukeiamyourfather]

The DOP caches store everything. As far as I know that's exactly what they're for. If you just want points then do it at the SOP level. Lets say you have 10 substeps now and 24 FPS, change the FPS to 240 (substeps times FPS) and change the substeps to 1 then cache it out at the SOP level. If there's a way to do this at the DOP level I'm curious to know and someone please correct me!

[Sierra62]

You can also use a time blend with a time warp to slow it down after you cache it out.   If you aren't adding lots of particles this tends to work really well.

[haggi]

Oh, yes. Changing fps is a good idea. Until now I only changed the time scale in dops. I simply used a dop file node and exported the substeps with $SF. Then I read the result with $F what reads a substep per frame. Works fine. I'll test the fps modification.