Curvature Comb in Geometry nodes - half way there

Hi, I believe this could be useful for modelers out there, Im trying to make a curvature comb for surface diagnostics in Geometry nodes.
Im able to make a curvature line for given point on a curve, but I dont know how to do it for All the points of a curve.
Im using 3-points circle to get a local radius. Any ideas how to do it for all the points with Instance on points or something?
Curvature Comb.blend (1008.3 KB)

Link to Stack Exchange question

I think instancing won’t work. Making chained groups and looping them works but it is a bit messy.

Curvature Comb-groups.blend (2.4 MB)

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Thank you, but I need this to work on arbitrary geometry, this doesnt seem to be the way.
I guess we need to wait for FOR loops? If that ever happens

Yeah with “for loops” that will be much easier less messy. I think loops will come, it is in the planning.

But this works in any geometry. You can draw curves at any part of the mesh using " shortest path node" and you can cover all points in that curve by dublicating node groups.

hmm maybe this is possible with instancing using sample curve and new curve topology nodes but I don’t know how you calculate this curvature stuff.

Good luck, that might be a useful tool.

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Hi, I made some curvature combs for bezier curves, it took me long but it works quite well and it’s very fun to pay with! Maybe you are interested :grinning:
Bezier curvature 20230415.blend (3.4 MB)

It is based on the exact formula so it works only for bezier curves. However I tried to make a version for discrete curves with “Menger curvature” (found here), but It doesn’t work and I haven’t found the error yet.

The discrete version should work on meshes like yours.
I keep you up to date if I find something new.


Have you watched this yet?

Also watch his Corner Instancer video.

Watch all his other Blender videos too - for useful math.


Thanks guys!
Havent been here for some time, these things look cool!
However meanwhile I managed to make my own version (looking forward to look at RomainGuimbal’s one).
It is here, Assets are for free, with paid UI version.
Surface_Diagnostics_Assets.blend (2.3 MB)

Thanks everyone for support