1. Hi there,

    The breaking threshold doesn’t seem to influence the clumping in any way. Although I can read the breakthreshold in the null geo spreadsheet. Any idea’s why? I am using Houdini 18, maybe version difference?

  2. Hey, I also struggled to get this working, double and triple checked my settings but didn’t get clumping. My attributes look the same as in Mo’s file as well and exprimented with extreme values for both threshold and stiffness. Not really sure what I’m doing wrong here!

  3. I had the same issue.
    In the vellum solver, go to Advanced > Motion, and turn off Normalize Stress.
    That’s the missing setting from the video that is present in their scene file.

  4. If I copy this setup, or open the provided project file, it breaks if I jitter the points. Instead of the grains just falling, they have an initial velocity that pushes them away from eachother. Anyone have any idea what I can do to fix? Im in Houdini 19. Thanks

    • ah, silly mistake. In H19, make sure to tick ‘Adjust Radius to Avoid Overlap’ on the Vellum Configure Grains or else the grains will fly every. I’m guessing previous versions did this automatically before the introduction of vellum fluids, which uses overlapping particles.

  5. I’m a couple years late to the party here, but just wanted to point out that as an alternative, more art-directable way of creating clumps, put a pointvop on between the constraints_grain and vellum solver, create a greyscale noise and output to Cd, then use a point wrangle to make f@attractionweight = @Cd.r.

    In the vellumsolver, under the advanced tab, use “Attraction Weight” as a multiplier.

    You can use this instead of, or in conjunction with the cluster/glue constraint method.

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