Explosion Dynamics using DOPs

[pinkmouse]

Hi folks.

 

So, I'm a newb in Houdini.  As a PLP, I'm trying to create a shot of a slow motion explosion, with a shockwave coming out and shattering panes of glass at various distances from the blast. I've got the pyro sim sorted, I'm creating the actual shockwave in Fusion, (though I'll try it in Houdini eventually), but am having problems with the actual shattering of the glass, and would appreciate advice on the workflow.

 

The tutorials I've found seem to only deal with hitting fractured objects with other objects, so I tried this to start, but was unable to get my transformed, (scaled) sphere to interact with the glass, despite using the "use transformed object" settings in the solver network. So I decided to use a magnet force instead, thinking it would probably be better in the long run as I could scale down the force over time and expansion to get the correct falloff.

 

But before I got around to that, I started having problems with Glue. If I have it turned up enough to resist self collapse, it doesn't break with the magnet  force, If I turn it down to get a nice shatter, then it all falls apart before the blast hits it.

 

So, have I even got the right workflow for this? Am I missing something obvious, (probably! )?

 

I'm not after a node by node breakdown type solution, just guidance on which way to go as there seems to be many ways to do this sort of thing in Houdini, not all optimum. I've included a simple scene file for your perusal.

 

Thanks in advance!

 

 

Explosion_v004.hip

[Farmfield]

Very controllable way to setup explosion is through a velocity field, something pretty easy to setup from a point loud, then feeding the velocities right into the simulation. I have a simple setup linked in the description of the demo.

 

[pinkmouse]

That looks really interesting, a very useful technique, and one I shall steal .

 

But it doesn't really help me with this one I think. I would like the explosion to be an expanding shockwave, as seen here:

 

 

...that breaks the panes as it passes over them. I could fake it by offsetting your velocity sims, or even just nailing it together in comp, but as it is a learning exercise, I'd like to do it right at least once, even if it never happens again!

 

 

[Farmfield]

The whole point of the type of setup I'm talking about is shaping an explosion so you not only can but should drive an explosion like that with a velocity field - though a more or less linear one from the detonation point.

 

And you could argue you should set this up in the Pyro sim, but that won't look very realistic - or at least not very interesting - better create a very turbulent explosion and then force it in to the dome shape, it will look better/cooler/more realistic.

Edited December 28, 2015 by Farmfield