pyro question

[catchyid]

Hi,

My fire simulation does not ignite, i.e. I have a temperature and fluid fields, but they don't turn into fire? What is the right/fastest way to troubleshoot that? I've tried blindly doing couple things like decreasing the ignition temperature (to zero), scaling fluid source SOP fuel and temperature field, etc. but nothing really worked. Is there a panel that should help me pinpoint the problem instead of doing things blindly?

Thanks

 

pyro_problem.hiplc

missile.bgeo

[johnLIC]

I'm not sure if this is the problem you're trying to solve, but the emitter works if you turn off the gasresizefluiddynamic1 node.  You can give the emission a chance to start by setting the Delay Frames to something like 10.  I would also make the initial pyro box bigger.   Delaying, and increasing the pyro size both give the resize node a chance to sense some density before collapsing the pyro box on itself, if that makes sense.  There's also something weird going on with the timeline for me.  If I step through manually I can see the sim, but if I press play I end up at frame 2.63, 3.63 etc, and there is no density to see in the viewport. ???

Edited November 14, 2016 by johnLIC

[catchyid]

Thanks John a lot! You nailed it down. The problem was due to two things:

-gas resize fluid : Delay Frames was to zero which collapsed the pyro box quickly

-my playback allowed floating point frames, e.g. frame 1.2 or 2.3 --> For some reasons, Houdini did not interpolate the result, it just displayed nothing at frame 1.2 ignoring frame 1 and 2 results...

Alright, once more, thanks