Yarnworks: Wire Solver and Constraint Networks in DOPs

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Free Tutorials

To complement our PBD Wire Setup, here is a tutorial on a topic I’ve personally been struggling a lot when I first tried wrapping my head around constraint networks. Similar to what we’ve been doing in PBDs, we’re gonna build a network of interconnecting wires – this time using Houdini’s wire solver.

Disclaimer: I wouldn’t have been able to pull this off without the help of Matt Estela’s CGWiki. Also nowadays we’d most likely use the grain solver (PBDs) to simulate something like the setup shown here. It is usually much quicker without giving much different results. Nevertheless should you run into a situation where you had to use constraint networks – here’s how they work.

Download Project File (.hipnc)

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  1. Hi there,
    Thank you guys for all your tutorials, they are really useful, please keep it up! 🙂
    Now, this is not just easier with a spring node and some pinned points?


  2. Juan Pablo De La Rosa

    Really guys, thank you, without your tutorials I wouldn’t have ever been able to extend so much my present knowledge of Houdini. True inspiration in many ways!! I wish I could be in the capacity of supporting you in Patreon hehe someday in the future my finances will allow me to.
    Oh and Matt Estela’s wiki is amazing too! He offered the solutions for so many problems I encountered. The building of constraint networks is something that I still ponder upon while I walk from here and there.
    Thanks again and keep up with the quality level!

  3. I want to recognize you, this work was very complicated in the VEX and very confusing, and I get to the end fighting about…so, honestly it was very good : )

  4. Craig Speakman

    Thanks again for another inspirational tutorial.
    I had trouble recreating this effect and after disecting the sample file i think the error came from the attribute create (at 8 mins) the anchor_id attribute needs to be set to integer.. I think after i set that everything worked.

  5. Hello,

    Nice explanation of constraints networks, but cannot the same be achieved in a simpler way just with a fuse before the wire sim?

  6. Hello Entagma!

    Thanks for the informative tutorial! I’m having trouble getting this to work in Houdini 17.5…I have re-watched this video several times and for the life of me cannot figure out why it will not work. It seems that the constraints are not working and the wires just fall down in the same way they did before you went through and corrected the setup.

    Do you know if anything has changed since H16 that would cause this to break?

    • Hey guys, do you know whether the self collision of the wires could work with this setup? When getting up close with collision settings checked and sampling increased, wires still seem to just pass through each other.


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