# Extrude surface to boundary

Hey, i am trying to exturede hexagonal surface and try to use other surface as a boundary, but when i rund the command, it says “The selected surface doesn’t form a boundary for the extrusion.” and the hexogans extruded way much higher then the boundary suface. Can anybody help me on this?

Hello - from the images, it looks like the target surface crosses the inputs, maybe? - the surface should be on one side or the other.

-Pascal

Hey pascal, thank you for quick respond again. They are no crossing each other. I noticed that might be the case and fix it but the result is still the same. But i am sure they are not crossing.

Hello - can you post a Rhino file with all the inputs?

-Pascal

Here it is, i try to exturede the hexagons so that reds will reach 1.75mm thicknes, blues 1.5 and greens 1.25. But at the edges of greens they need to have 0.75 thickness.

hexagons.3dm (13.1 MB)

Hello - it looks like the problem is there are non-manifold edges in the extrusion -

-Pascal

1 Like

hımm, i didnt know a non manifold egde can couse that kind of problem. By the way, when i run the showedges command, there is not any nonmanifold edge detected.

Hello - you’ll see them on the extrusion. The reason it is a problem is that the extrusion to the boundary is essentially a BooleanDifference operation, and Booleans fail when there is not a clear inside and outside of the input objects, as when there are non-manifolds.

-Pascal

Oh okay then, i will try to solve that problem then!

Hey, i fixed that edge(totally delete it) and there is not any non manifold edge when the surface extruded but the result is still the same

Hm. Can you send the surface to extrude as it is now and the target once again?

@karakusc - make your surface from the curves in the attached file and extrude that -

Hexagons_PG.3dm (699.3 KB)

I found every location that looked like this:

and made it look like this:

(And ran `SimplifyCrv`)

-Pascal

Nothing changed unfortunately

When i try to do it with simpler surface(flat one just rotated little bit) i still not working.

That worked thank you so much!