Offset Question

Hello All,

I am trying to offset a wavy surface by 3mm. (The surface is originally sweep2 but also works when I loft between the two rails - have tried both and none work).

When I offset by less distance (say 0.15mm) it works - I can do an offset surface without self-intersecting faces. However when I offset the amount I need (3mm), it intersects with itself, as you can see in the image attached. I have tried OffsetLoose but as I am fairly new to Grasshopper I am not quite sure which variables I am playing around with...

I suspect this has a fairly simple solution and would appreciate your help. Bear in mind I need to do 35 offsets like this (the final aim is one airtight mesh).

Thanks in advance

ptr

Replies to This Discussion

Permalink Reply by David Rutten on April 24, 2013 at 2:46am

OffsetLoose will only move control-points. The proper surface offset will insert control-points if the surface in between the offsetted control-points deviates too much from the offset distance. but even the Rhino surface offsetter won't handle self-intersections. You can see this just by using the OffsetSrf command in Rhino. I can't find anything in Rhino that would do this, we may not have the algorithms for it.

The closest I could get was using _OffsetSrf and then _Drape:

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by ptr on April 24, 2013 at 3:27am

Thank you!

Drape doesnt do it for me as I have several orientations. (See Image)

Do you know if I can 3D print with non-manifold edges or self-intersections?

Thanks, regards.

Permalink Reply by David Rutten on April 24, 2013 at 4:40am

I think you can print with intersecting shapes, non-manifoldness is probably a bigger problem. However you'll need to talk to your local print shop for that.

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by ptr on April 24, 2013 at 4:41am

Thank you, very helpful :)

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