Pyro advect from pyro thats emitted by particles?

[caskal]

Hey magicians,

I've got a particle setup burst wich generates a pyro sim

I know how to advect particles from pyro when we have ie: the same emitter (sphere) but in this case my main emitter is this particle system:

So what I tried to do to have the base geo emitter match with the pyro shape is: 1) copy spheres on the particle emitter - 2) create a vdb from the pyro and use as source

Both methods don't get me that pyro shape in motion with the particles, any suggestions?

Thanks!

[evanrudefx]

I have an Idea. You know the particle source you used for the initial explosion? Duplicate that setup and use it again. This time, just remove what ever is generating the explosive outward force then use pop advect instead.That way the source would be the same, you are just getting the motion from the pyro sim instead. 

[caskal]

@ejr32123 thanks for the help! I tried that without luck. I also did a test with a setup that always seems to work but for some reason (maybe the particles that drive the pyro are too fast), the emitter doesn't seem to follow the pyro, instead it goes in any direction all the sphere

 

this is the setup

[evanrudefx]

@caskal could you post the scene file? I could look at it. Also, I would probably do it in another dopnet.

Edited September 11, 2018 by ejr32123

[caskal]

@ejr32123 that would be awesome, this thing is driving me crazy I'm about to resign and find another way to create the powder burst and advect it, what the client needs is that pyro sim I did but made of a bunch of particles.

I deleted all the innecesary stuff on the scene and orgainzed a bit to avoid headaches, the sim starts at frame 258

P.S: Thanks for the advice on the dopnet, I tried that without luck haha don't know what else to try.

Attached is the hip, will keep digging around this, thanks!

powder_explode.hip

[evanrudefx]

I think the reason its not working is because of a few things:

1. the source your particles are coming from is extremely small. 
2. the resolution of the your pyro sim is large

Its almost like your whole particle source is the size of one voxel from the pyro sim. All the particles are being advected from like 3 or 4 voxels. For a sim that expands that fast I don't think you need a source that small. Anyway, I just used a a bigger radius for the sphere controlling the particle's source, and they starting advecting much better.

[caskal]

I think you are right, now I checked the source is super small, I was trying to match the client scene scale wich was a pain in the ass, I'm doing some tests making the stuff following a normal houdini scale, thanks for the help!!

[evanrudefx]

I usually just scale what ever I do. I found for me its best to work in meters, then scale to match what the client needs. good luck!

[caskal]

@ejr32123 good to know, thanks for the tip and the help! cheers!

[Jesper Rahlff]

you can just source directly from the particles if you want? in the source volume node in your dopnet, you can tell it to source from particles rather than a volume.