FR : 'Simulation Speed' for the Fire effect.

skitchyskitchy Website User Posts: 43
edited September 2015 in Post-production techniques

Currently the flames generated by the Fire plugin can seem a bit too slow/fast depending on the size of the fire you are envisioning. Currently the workaround is to use the Time plugin, but this is quite processor intensive. I'm sure that internally there is a variable in the fire simulation that controls its time-step - I would like access to change that variable. This would also add a bunch of new uses for the fire plugin, especially if the time-step could be reversed and keyframed. I'm sure extreme settings could give some weird and wonderful results ;)

Comments

  • RobinRobin Website User, HitFilm Beta Tester Posts: 1,671 Enthusiast

    If you go into the controls of the fire effect, there are a lot of values you can tweak to get just the result you want. Not at my editing PC right now so I can't tell you exactly what value to alter to make the flame speed faster or slower, but there definitely is a control for that.

  • Triem23Triem23 Moderator Moderator, Website User, Ambassador, Imerge Beta Tester, HitFilm Beta Tester Posts: 18,227 Ambassador

    Check out this tutorial. It's for HF 2, but everything works the same way if HF3. Simon covers all the Fire controls. 

  • NormanPCNNormanPCN Website User Posts: 3,945 Enthusiast

    I think I am with @skitchy on this one. I don't see a control to adjust the flame movement speed in the fire effect. Maybe I am blind, but I have tried them all. Maybe not in certain combos.

    The speed effect is quite slow and can cause blurring due to frame blending. 

  • skitchyskitchy Website User Posts: 43
    edited September 2015

     As far as I can tell, there is no direct 'simulation speed' control. It all depends on how the other parameters are set in relation to each other. My point is that I got some fire looking exactly how I wanted it by tweaking the parameters and watching the 'still' image update. But when I started playback, the animation of the fire was too slow. So the look was right, but the timing was off. This might not happen if we could playback effects while tweaking their parameters, but we can't. So in lieu of that I think it would be nice to be able to alter the simulation speed independently. It would almost certainly be a trivial thing to implement in code as well.

    And while I'm asking, I think this would be a good addition to all the other simulation plugins as well (like particles).

  • Triem23Triem23 Moderator Moderator, Website User, Ambassador, Imerge Beta Tester, HitFilm Beta Tester Posts: 18,227 Ambassador

    The particle sim actually has a full Time Scale slider that can be keyframed to speed up, slow down, and even reverse the sim. 

  • skitchyskitchy Website User Posts: 43
    edited September 2015

    Ah okay, I haven't looked into the particle sim yet. But it bolsters my point about the fire sim needing the same function ;)

  • KadriKadri Website User Posts: 171

    I rendered some parts at 100 fps out and comped that in a normal 25 fps video when i needed it. A little more work but you can use this basic method for other things too when you want very slow effects.

  • skitchyskitchy Website User Posts: 43

    Could I get an answer on this please? It is still annoying me that I can't just adjust the simulation speed of the fire effect. Fiddling about with separate temporal FX is slow, clunky, and looks crap.

  • StormyKnightStormyKnight Moderator, Website User, Ambassador, Imerge Beta Tester, HitFilm Beta Tester Posts: 2,726 Ambassador
    edited March 2016

    @sketchy - Did you try adjusting the Movement control in the Fire effect? If you set it to 0.2 it moves slowly and if you set it to 3.00 it goes fast but the flames increase in size the faster you go which makes sense from a real world application standpoint. I'm not sure if that's the answer you're looking for. OR- have you considered modifying the Bonfire effect? You can turn off the smoke and embers so you just have the fire. You can adjust the spread, ferocity, intensity and size and keyframe the changes where you want them.....except for ferocity but you can simulate fast to slow without having to adjusting ferocity.

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