Offset Grasshopper

Hello everyone,

I’m having a problem offsetting a joined surfaces.
First image shows the two separated surfaces (red and green)

Second images shows the two surfaces joined.

Third shows the end result. I have matched branches. As you can see offset is not only not doing its jobs, but it has created a new surface/cap.

Fourth has the different branches but is offsetting both surfaces by them selves.

This is not the first time I come across this issue with Offset. I have flattened but still this does not work.

Does anyone have an idea as why is this happening? Should I check surfaces normals?


If you want help, better post your Grasshopper file with the relevant geometry internalised.

Yes sir, I missed that part. Here it goes
offset problem (22.5 KB)