Looking at docs and tutorials, Houdini's rigid dynamics is full of features and the fracture tool appears to work well. But, what blockbuster vfx film has recently used it, who is using it?

asking that in houdini forum the most obvious response you will get is, houdini.

but being neutral myself, yes, houdini has maybe the most easy to use, and powerfull rdb system.

it doesnt mean that others 3d packages arent good at it, is just that houdini is more focused on that.

you may see what has been done in houdini in the main page

all is about tastes, due that im a fanatic of fractals and procedural techiniques, i would prefer houdini lol

Understood, it's just I see so much attention paid to Houdini's Fluid and Particle systems and not nearly as much on Rigids. Hence the thread.

Was it Digital Domain that ran all those destruction sims? Did they use Bullet plugged in to Houdini or what?

I guess a good argument would be tbat running Houdini rigids works well when running secondary Houdini particle passes. It's an all in one package to emit particles after breaking rigids.

Different RBD systems have different strengths. Houdini has it's own RBD Solver as well as OpenDynamicsEngine support built in.

Houdini's is faster for complex shapes and ODE is faster for primitive shapes. Each expose some unique capabilities (Impact records, etc) and so on.

The important thing to note is that with Houdini, much of the same base setup can remain the same and you can swap out a different solver to compare performance and results.

There is also an open-source Bullet Physics Solver DOP you can compile and use with Houdini.
http://code.google.com/p/bullet-physics-solver/ [code.google.com]


Pick yer poison

jason_iversen
The important thing to note is that with Houdini, much of the same base setup can remain the same and you can swap out a different solver to compare performance and results.

Good to know, so then learning Houdini makes sense to me.

Another plus with RBD's in Houdini is the fact that you can muck with the geometry feeding in to the RBD system and also muck with it after the simulation all in the same Houdini session.

You don't have the traditional model>Animate>Sim> cache-to-disk > light and render pipeline.
You get this meandering circular path to madness that you simply have to cut off at some point in time to deliver your stuff.

lemond
Was it Digital Domain that ran all those destruction sims? Did they use Bullet plugged in to Houdini or what?

Yes, son-of-Bullet, which we called Drop, was used for 2012. While I wasn't part of the RBD team, I used the results. 35,000+ items in the sims, all pre-fractured and randomly glued together, then they'd break if the forces were strong enough. Definitely not an off-the-shelf setup, though. A lot of custom work got put into the setup to make it feasible.

In comparison, Houdini's RBD system will start to bog down after 400+ items (though it's tunable by how fancy you get with the collision models). I can't imagine trying to jam multiple thousands of pieces through it.

jason_iversen
Different RBD systems have different strengths. Houdini has it's own RBD Solver as well as OpenDynamicsEngine support built in.

Houdini's is faster for complex shapes and ODE is faster for primitive shapes. Each expose some unique capabilities (Impact records, etc) and so on.

The important thing to note is that with Houdini, much of the same base setup can remain the same and you can swap out a different solver to compare performance and results.

There is also an open-source Bullet Physics Solver DOP you can compile and use with Houdini.
http://code.google.com/p/bullet-physics-solver/ [code.google.com]




Pick yer poison

http://code.google.com/p/bullet-physics-solver/ [code.google.com]

Sorry, it's not clear to me to how to compile, any step by steps for windows7?

Since Bullet is faster, why hasn't everyone switched from Houdini's solver to Bullet solver?

lemond
Since Bullet is faster, why hasn't everyone switched from Houdini's solver to Bullet solver?

Well, as long as all your geometry is convex, you're ok. That pretty much rules out any complex shapes without some significant preprocessing work to make subshapes that are all convex but add up to the original. For example, the letter ‘C’ is very much *not* convex! It has a lot of interior space, but Bullet would treat it as an ‘O’. You'd have to chop it up into a bunch of short segments and “glue” the segments together. Not too hard with something as simple as the letter C, but distinctly un-fun with a shape that has sin() waves on it, and we're talking static geometry here! No animating sin() waves :-(

So the tradeoff is, got simple, convex shapes, use Bullet; anything else, use DOPs. Oh, and forget RBD -> cloth/water/gas interaction with Bullet! It does RBD only.

P.S. I have no experience with Maya's RBD system.