Hi all,

I'm running into an issue with Vellum Configure Grains in Houdini.

In all the tutorials I’ve followed, the Vellum Configure Grains SOP produces a point separation that looks fairly tight — with particles (grains) densely packed. But when I create the same node in my current version of Houdini, the default separation appears nearly twice as large as in the videos.

I'm trying to figure out:

What might be causing this discrepancy?

Is there a global parameter or project scale setting that could be inflating the separation?

Will this affect the accuracy or realism of the Vellum simulation? (e.g. falling speed, collision behavior, grain friction)

So far, I'm using default settings and standard geometry (like a sphere or box). I haven't intentionally modified any scene scale or units.

Check which Houdini build you are running, there were a couple 20.5 prod builds where pscale was changed from radius to diameter in the Vulkan viewport only. If you get big gaps between grain points when viewed as lit spheres, chances are you are running one of those 20.5 builds. The problem should be fixed in a more recent production build.