# Offset non planar surfaces

Hi, I’m new here. I would like to know how I can offset non-planar surfaces. I need to reduce all these panels leaving a standard distance between them. I tried to do this with scale but the result was not so good.

It’s helpful to upload a refence file, a rhino or (ideally) a grasshopper file with internalized geometry.

That said, if you can split that surface into the (28?) sections with edge curves, you could use the “Offset on Srf” component with a negative input to achieve that.

Another way is to use Unroll surface and then turn History recording and draw rectangular closed curves on the latter. Then use Orient on surface to place those curves on the target (original) surface. But keep in mind that the resulting oriented curves will not maintain the same offset distance everywhere. However, one advantage is that this approach let’s you quickly modify the resulting curves by adjusting the input curves on the unrolled surface.

To upload a file click on the vertical arrow icon above where you type a post, or drag the file to where you type a post.

How is that standard distance measured: along the surface or in the flat plane?

If it is in the flat plane thena method for Rhino:

Go to the Front viewport so the Cplane is the xz plane.

ProjectToCplane the dividing lines including the boundary to obtain a set of planar curves.
-or-
Draw the dividing lines on the Cplane

Offset each planar dividing lines to both sides half the desired spacing.

CurveBoolean the offset curves. Select the regions which will be the tiles.

Trim with ApparentIntersections using the results of CurveBoolean
-or-
Project the results of CurveBoolean onto the non-planar surface
Split
Delete the unwanted parts

Yeah, a variation on this idea is:

1. Surface Split the wavy surface.
2. Project the surface fragments as curves onto the XZ plane.
3. Offset the projected curves to get the desired “final cut” curves.
4. Project the offset curves to the original wavy surface and Surface Split it.
5. Delete the unwanted parts.
1 Like

Thank you very much, this solution helped me to solve my architecture course completion project