Extrude straight - "input was not extruded because it would have made an invalid surface"

Rhino Rhino for Windows
1

Hi, architecture student here using Rhino for the first time on a project and hoping to get a little help.

I’ve created a set of curves from some site data and lofted them to create a polysurface. Then I created a grid and projected the grid onto the surface, giving me the outline of a gridshell structure. What I’m trying to do now is give the outline some actual structure by extruding the lines up and then sideways by 0.4m to create structural members.

When I try to extrude straight (vertically) I get the error “One input was not extruded because it would have made an invalid surface.”

Anyone know why this would be and how I can extrude these curves? Is there any analysis I can do on the curve to see why this would be the case? File is attached. Thanks!

Form 5B.3dm (846.0 KB)

2

Well, looking from the “Top” view, I might start by extruding all “horizontal” curves a small distance both sides (like 0.1mm) in the Y axis direction; then do the same with all the “vertical” curves in the x axis direction. Once done you have a series of curved ribbons; you can select all of those and use OffsetSrf with the solid option to create a uniform thickness curved beam on all.

Form 5B_msh.zip (4.9 MB)

1 Like
3

That’s magic, worked like a charm! Thanks!

Form 5C.3dm (11.6 MB)