Emit Smoke From Interior Face Group Of Fracture?

[Atom]

HI All,

 

I am looking for a modern solution to emitting smoke from the faces of a fractured object. And by modern I mean Houdini 15 or better. There are some old threads floating around on this topic that go back 5 years or more. I want to avoid using depreciated nodes or techniques.

 

In my example scene I have a torus that I have fractured and made breakable. This works, the torus breaks when it collides. I then clicked on the Wispy Smoke tool and choose the torus. This turns the entire torus into a smoke emitter.

 

I thought it would be a simple task to filter the faces where the smoke comes from, but this is not the case for me, I can't figure it out.

 

I am creating the inside group from the Assemble but that group is only valid until the volume is created.

 

The faces I want to emit from don't actually exist on frame #1, when the torus is whole.

 

Does anyone have any information on how to accomplish this task using Houdini 15 or better?

ap_my_torus_emits_smoke_from_fracture_1b.hipnc

Edited November 22, 2015 by Atom

[borbs727]

I could be wrong, but using a debris source sop to spawn particles from cracked geo and emitting smoke from those particles might be the latest technique (or at least one of them).  I'd post a file but I'm not at a computer with houdini right now

Edited November 23, 2015 by borbs727

[Atom]

I read somewhere that the Debris tool is an older tool that uses the H12 particle system and therefore is not compatible with H15 collisions.

 

Also, I could not actually get the tool to work. The work flow seems flawed. I select my object click no the tool and press enter and all that and it did not work.

[borbs727]

Take a look at the attached file.  I didn't have any issue creating with the debris tool.  Also, at first glance the dop network for spawning particles looks like a recent one (the older one uses a separate particle environment I think).  

 

If you want to emit from the geo and forget about particles I've added the setup in there.  I use the debris source sop points as an attribute to let me know when pieces have broken.  I then give those points a color, transfer the attr to the original geo and delete prims that belong to the outside group and any prims that aren't red.  From there you can do a regular pyro setup.

debris_fracture.hiplc

Edited November 23, 2015 by borbs727

[Atom]

Thanks for the example file Mike. I have been playing around with debris this morning. I guess what initially disappointed me about the debris shelf tool is that it is it's own sim and is not linked to the RDB sim, at least not the ground plane. I figured out that you have to manually copy the ground plane static solver from the AutoDopNetwork into the debris_sim for the debris to collide with the floor.

 

You mention your setup is ready for pyro simming. How would I proceed with that?

This is a main stumbling block for me in this area. You have points and faces separated yet how do I tell the Billowy Smoke shelf tool to use those? The status message when I use the shelf tool instructs me that the source must be an object, not faces or points.

Edited November 23, 2015 by Atom

[borbs727]

No problem, Atom!  

 

The debris_source node (at scene level) contains all of the geometry from the fractured simulation.  By deleting the unwanted faces, I'm not really changing the type of data coming out of that sop (it's still a primitive) it just has procedurally deleted faces.  Just select the debris_source node (at scene level) and ctrl+left click the pyro tool that you'd like to use.  This will create the pyro network in the same dop node as the particles- so just make sure to unhook that pop simulation from the merge sop to clean things up a bit.

Edited November 23, 2015 by borbs727

[Atom]

Thanks again for the info I did try what you suggested and I do get a pyro sim in the main Autodop Network, however, I see no smoke in the viewport or when I render. Is that normal?

 

I have attached your file with my attempt at adding smoke if you have time to take a look?

ap_debris_fracture_smoke.hipnc

[borbs727]

Not sure how to specify what DOP network a shelf tool should build in, but when I create the pyro in my file it builds in the correct one (debris_sim).  Your file kept building the sim in the AutoDopNetwork_fracture node.  Here's my file

debris_fracture_withSmoke.hiplc

Edited November 23, 2015 by borbs727

[Atom]

Thanks Mike, that was it! Your example is what I was hoping to achieve.

 

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PS: I was able to get the PyroFX to install into the debris_sim by simply using CTRL-X to delete the existing AutodopNetwork, running the PyroFX tool as you suggested in previous post, then using CTRL-V to paste to AutodopNetwork back into the scene after the Pyro tool has run. This cause the PyroFX tool to install into the only available network which was the debris_sim.

 

I'm using H15.303 and I'm starting to think the PyroFX tool has a slight bug in it's detection of network code.

Edited November 24, 2015 by Atom