Apologies, it's been a while - I want to drive point color (using a point SOP) using the curvature point attribute generated by the measure SOP, but I can't remember how to move the data over to the point SOP in a useable fashion. I think that it's a nomenclature issue that I'm struggling with.

Edit:

Nevermind, solved:

point(“../measure”, $PT, “curvature”, 0)

Like I said, it's been awhile.

Wrangle it!

All the kids these days are using Attribute Wrangle SOP to mangle attributes about:

@Cd = @curvature;

or

@Cd = fit(@curvature, 0, 50, 0, 1);

as curvature values can get quite large.

Good tip, thanks Jeff! I briefly looked at the newer Attribute Wrangle SOP before I chickened out and went with old faithful.

jeff
Wrangle it!

All the kids these days are using Attribute Wrangle SOP to mangle attributes about:

@Cd = @curvature;

or

@Cd = fit(@curvature, 0, 50, 0, 1);

as curvature values can get quite large.

Oh, one other thing - the measure SOP allows you to normalize the curvature values if need be, which is very handy in avoiding those large numbers.

Oh, hey, while I'm on the topic - what's the best way to distinguish between concave and convex?

is your geometry closed? if so, you build a level set, compute curvature via vdb analysis (which yields positive/negative values per convex/concave), then transfer the data back to your geo.

if your geometry is not closed, you have the problem of the same feature being concave on one side, yet convex on the other. however, if you have coherent normals, you can work something up in a vop that inspects your normal and your neighbors to get the sign of the curvature. with that, in conjunction with the measure sop, you should be good to go.

That's great, good tip! I'm just getting familiar with the VDB stuff to be honest, I never even thought to look there. I've been going from polys to VDB and back again in order to make some of my patchwork models continuous and water tight.

This information is great! How would you then use that to put it in a group for selecting those faces later? Sorry, noob here. Thanks!