Grasshopper planar surface

thank you i will go your way and try

hello @magicteddy
I followed the path you showed but failed, few flat surfaces, where am I going wrong?
i am sending the file
oval (8.1 KB)

oval .3dm (80.7 KB)

Your ring is not convex.

How can I apply this surface?

positive on the sphere surface

Seems the problem already showed up a few years ago.

Concave shapes are… problematic :sweat_smile: Try to apply the method on two half “moons” ?

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I tried it, it didn’t work, it happens on all extroverted surfaces

@magicteddy @DanielPiker answered on the forum and sent me this locust file, it works with this formula, but the patterns are in equal measure
Can it be adjusted so that its flat surfaces are not symmetrical? (8.7 KB)
sample.3dm (406.6 KB)


I couldn’t apply the grasshopper file you made to this

[copy-pasted the PM answer]


With a perfect cylinder, using tangent planes means all cuts are parallel the axis. So this would give some long rectangles. It could work but with Populate used on a circle and not on the surface, then simple build a polyline and extrude.

One idea to keep the original design is to define a cylinder with a slightly bigger diameter in the center (here 3.6 instead of 3.5) using Loft, and add a cutting procedure to the sides at the end. (13.7 KB)

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hello @magicteddy
thank you very much for your help, i got a little closer so far thank you very much

i have a question to you
how to make facet surfaces bigger
How can I change the lineup direction?

Reducing the amount of points should be enough.

Due to the randomness included in this solution I think it’s going to be very difficult to force the shape into exactly what you want. But you could try to force some points to have the same X coordinate for instance, this should give something more regular.

Where should I place the x coordinate point?


In your example it looks small, in my example it looks big.


Change the plane size.

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Thank you very much

What I meant is you should not use a random generator ike Populate 3D but instead, place some points in a regular grid and see what it does. Brep | Plane, Divide Curve will be useful.
Maybe place 5-6 planes, intersect your surface and divide those curves in 5-6 points.

It may also be a good idea to experiment with points placed in Rhino on the surface, and reference them in GH. To test the effect of their placement.

A test on a scaled sphere… Not really sure it’s better than your current model. (21.9 KB)

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Thanks a lot for your help

Using a spiral to position the points gives some decent results for some parameters. (14.6 KB)