Hi, I'm still hammering away on PyroFX, or maybe its hammering away at me.

I'm currently trying to create a quick short spinning fireball burst that quickly dissipates. Unfortunately I can't seem to stop the fire soon enough. Or i'm left with trace amounts of fire lingering on the source.

I also have been having weird issues when I render. When I do a preview render it looks great but when I actually switch off preview I get uglier results. Almost like its lower resolution. The only way I've fixed this was by upResing my sim.

I've uploaded the scene file. If anyone has any answers, it would be much appreciated.

To dissipate the fire quicker: increase Burn Rate, decrease Fuel Inefficiency and shorten the time between the Gas Release keyframes.

The Preview is a version of Ray-Tracing, when it's turned off it will render with the selected Rendering Engine in the Mantra node. At default that is Micropolygon. The best setting is most likely Physically Based Rendering, make sure to go to the Samples tab in Properties/Samples and increase the Transparent Sampling to around 5-14.

Hope that helps.

Also it´s a bit odd to add your Geometry Normal to the heat field in the gas particle to field node.
I bet you would like to map that to the vel field and increase the substeps in the solver.
A easier way would be to bring your Geometry in as a field-force.

Ok I gave it a try this am with no luck. How do I bring my geometry in as a field force?

Quickest way to extinguish any Pyro sim is heaps of -ve divergence added in when you want to extinguish the explosion. Extinguish is the correct word as it looks like the explosion is sucking in on itself.

The example file is the default Explosion where the source_fuel is cut off at a specific time. Then an additional Source Volume is used to take the fuel but added to divergence * -1. Finally an additional Gas Calculate is used to take the density field (always treat density as the mask for the sim) and that is also mapped in to the divergence field with a *-1 applied.

This will suck your explosion in right good.


Btw this technique can be used sparingly where -ve divergence pockets are added to suck in parts of your explosion to create nice inward velocity pockets. If done right, you can make your explosion collapse inward to great effect.

Hey Jeff,

I got a large list of warnings on pyrosolver1 with this example. When I ran the sim the it seemed to run fine then it totally filled the container by frame 40 then faded out by frame 90 is this what was supposed to happen? When I attempted to render it everything was also blown out white.

Landin

I am quite interested in this. I am trying to create something like this http://www.youtube.com/watch?v=GmRASCHJe2Q [youtube.com] (see 32 seconds onwards).

It's a very fast and violent explosion and then after a second it gets pulled in a little. I have pretty much worked out the expansion but I can't work out the part where the explosion gets pulled in a little. I checked Jeff's file but it doesn't seem to be working as expected. Any help will be appreciated.

Thanks.