Guided Simulations in Houdini

In this video, I'm showing how to use the new guided simulation feature to make a crumbling stone man.

Edit: Something has changed in the latest build so you might get funky results. However, the only thing you need to change to get it to work, is to connect the first port to the assemble/group instead of the point deform. Check the scene file below.

Download Scene file here


COMMENTS

  • BabaJ 4 years, 11 months ago  | 

    I was wondering if you have a chance to try your set up with a build(if you have it installed) later than H18.287

    I've tried it with H18.318 and 348 and in both cases whether it's just with one input and ground plane or two inputs and Use Guides ticked on;

    That the geometry falls through the ground plane and spreads out in all directions. The second case(Use Guides) is the same, just with added forward motion.

    I'm wondering if there is a regression or change of parameter defaults in the daily builds on the RBDBullet Solver node.( I've noticed a number of times RBD Solver mentioned in Change Log since .287

    • mixepix 4 years, 11 months ago  | 

      Works ok for me in .346. Try the scene file that I'm linking to below

  • Follyx 4 years, 11 months ago  | 

    spreads out in all directions...
    Have the same Problem H18.0.327

  • BabaJ 4 years, 11 months ago  | 

    So I re-installed .287 and it works fine. So either it's a regression bug or defaults on the nodes parameter have changed.

  • mixepix 4 years, 11 months ago  | 

    I just tried it in .346 and it works fine for me. I've uploaded the scene file here: http://shortandsweet3d.blogspot.com/2020/01/guided-simulations-in-houdini.html
    See if you still have the same issue.

  • BabaJ 4 years, 11 months ago  | 

    Yes your 'second' hip file that you mention here works. But now I see why. In the tutorial you have the the points deform nodes output going into the first input of the RBD Solver, @ the 4 minute mark before you do the grouping of the arm work. Yet in this second hip you reference it's the other way around, you have the points deform going into the last input of the RBD Solver. This is the link to my post on the forums where it is set up like you have it at the 4 minute mark - https://www.sidefx.com/forum/topic/71492/

    • mixepix 4 years, 11 months ago  | 

      Ah, right. They must have changed something then. That's annoying.

  • BabaJ 4 years, 11 months ago  | 

    Here's a link to my post on the forums with the new hip file that shows how you do it with the hip you just referenced here and how you do it in the video. The file name is "Guided Simulations v2.hiplc" - https://www.sidefx.com/forum/topic/71492/?page=1#post-303054

    • mixepix 4 years, 11 months ago  | 

      Cheers, I've updated the text as well

  • Follyx 4 years, 11 months ago  | 

    fine. works

  • npetit 4 years, 11 months ago  | 

    The problem you're experiencing with the pieces flying everywhere isn't in the sim - if you dive inside the RBD Bullet Solver you'll see the sim behaving as it should.
    There was a fix that was pushed out to address an issue with animated and deforming geometry not making its way into the sim - this has for consequence though that you'll want your input geometry to be non time-dependent (at least not animated nor deforming) when not tagged as "animated" or "deforming", otherwise the transform pieces SOP will yield incorrect results.
    Pushing only the point deform into the guide sim input (last input on the RBD Bullet Solver) addresses that issue .

  • npetit 4 years, 10 months ago  | 

    The regression has been fixed in 18.0.353 and time dependent inputs that do not have a "deforming" attribute are now handled properly once more.

    • mixepix 4 years, 10 months ago  | 

      Ah, right. Thanks for the update!

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