If so, this cap is a rather significant hindrance.

Example: If I have a project 2 minutes & 11 seconds long, that's a 131-second sequence. If I can only have 100 seconds of fluid simulation time, and it's forced to span the length of 100 seconds to 131 seconds, then it's evidently not going to flow in normal/real time. I can increase the speed, but there's no real easy calculable formula between speed and length to attain that real-time appearance; you'd just have to evaluated it by what looks right.

Is there a better solution that I'm not seeing here? If so, how can I accomplish normal fluid speeds beyond the 100 second time barrier?

  • $\begingroup$ There is a setting that is restricting it. You can use any length. $\endgroup$ – VRM Sep 18 '15 at 18:54
  • $\begingroup$ Thanks, NoviceinDisguise. Any idea what possible setting it could be? :/ $\endgroup$ – Jesse Sep 18 '15 at 18:58
  • $\begingroup$ I'm trying to remember, I'll let you know if I find it later tonight. $\endgroup$ – VRM Sep 18 '15 at 20:46
  • $\begingroup$ Much obliged. :) $\endgroup$ – Jesse Sep 18 '15 at 21:06
  • $\begingroup$ I've tried changing this in the source code and it appears to work without issues. $\endgroup$ – gandalf3 Sep 21 '15 at 19:24

It appears this was an arbitrary limit no one knew the reason for. As of this commit the limit is removed (will be in 2.76 or any recent build).

  • $\begingroup$ gandalf3, I just tried creating a new test project in the 2.76 rc release, and it still has a 100-second cap. Will the change you mentioned not be included in this release? If not, is there any way I can change it from the downloads the Blender Foundation provides via their website? $\endgroup$ – Jesse Sep 22 '15 at 21:28
  • $\begingroup$ @TravLR Nope, it wasn't changed in time for 2.76. You'll have to use a dev build such as those from the buildbot in the meantime. $\endgroup$ – gandalf3 Sep 22 '15 at 21:45
  • $\begingroup$ Damn. Well, good to know there's something to look forward to in the 2.77 release. Appreciate the inside info', though! $\endgroup$ – Jesse Sep 22 '15 at 21:57
  • $\begingroup$ Looks like the 2nd RC of 2.76 has this fix included after all. :) Just tested it with the release published, today. Good news for all of us fluid designers out there! $\endgroup$ – Jesse Sep 24 '15 at 17:58

Fluid simulation lasts 100 frames by default at 25 fps so its 4 seconds, so you probably confused frames as seconds.

According to blender manual:

Baking always ends at the End Frame set in the Fluid domain time panel: If your frame-rate is 25 frames per second, and you want simulation time to be real-time, then you should (if your start time is 0) set your simulation end time at 131 frames / 25 = 5.24 seconds.

“Start Time” and “End Time” are expressed in simulation time (seconds): If you set Start time to 3.0, and End time to 4.0, you will simulate 1 second of fluid motion. That one second of fluid motion will be spread across however-many frames are set in your End setting in the fluid domain time panel. You can read more about fluid simulation on Blender manual. enter image description here

  • $\begingroup$ I'm not sure if I understand.. How does this explain how to make the fluid sim last longer than 100 seconds? $\endgroup$ – gandalf3 Sep 21 '15 at 0:18
  • $\begingroup$ Well just divide the amount of frames you want to simulate by frame-rate and type the result in Fluid simulation end time. $\endgroup$ – Photon Sep 21 '15 at 4:44
  • $\begingroup$ But what happens if you want to type in a number > 100 (as the OP seems to want)? $\endgroup$ – gandalf3 Sep 21 '15 at 5:13
  • 1
    $\begingroup$ Thanks for the suggestion, Photon, but the simulation I was referring to in my original post was a sequence lasting 131 seconds, or 3144 frames. 3144 frames / 24 fps = 131 seconds, which is what I was trying to have the fluid simulator achieve. $\endgroup$ – Jesse Sep 22 '15 at 21:29

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