Help with creating solid from surfaces that won't merge

Hi, I’m at a bit of a loss with this project!

I’ve building a series of low-poly animal heads from surfaces, and want to add thickness to these surfaces to create a hollow solid (think like a mask). My issue is, I can’t even get the surfaces to merge.

My end goal is to use OffsetSrf to thicken the “shell” of the mask, however currently while it runs and LOOKS like a solid, it actually fails to create a real solid, so I cannot print this.

Each surface was built off another surface, with snap to corners on, so I don’t understand why the surfaces aren’t perfectly abutted to one another.

Using Join results in creating an open polysurface, which then allows me to use OffsetSrf, but while it adds thickness it doesn’t create a solid and has holes.

MergeSrf works with a very small percent of the surfaces, but for most it says “Edges are too far apart to merge”.

ShowEdges set to show naked edges suggests that nearly all my edges are naked, which again confuses me because as I built this form, each surface was built off the last with snap-to-end points enabled.

I’m really stuck and any help would be appreciated, thank you! fox help.3dm (3.4 MB)

Hello - please rty this:

  1. Join all the surfaces.
  2. OffsetSrf > Solid=yes, .065 or .07 units.

You can also mesh the joined object and OffsetMesh to get a mesh directly.


It still says “OffsetSrf failed to create a solid.”

It does Offset the surface, but it’s not closed (aka watertight).

hm - well, that would be the general propcess, but looking more closely I can see where things might go awry - the ear for example


And Join leaves a couple of internal edges unjoined (ShowEdges > Naked edges) so that will need a fix. basically you need to set up the starting shell so that the offset at the distance you request makes sense.


Is there any way to make these surfaces match edges? I thought I the snap to edge being turned on would be a surefire way to avoid the issue.

Hello - there are two things here, I would say - one is, naked edges internal, as it were, to the object - not on the outer edges, after the Join. There are two of those. ExtractSrf, Delete and make a new surface for each with a Loft across two of the edges.
The other is areas like in my image where the faces make such a tightly convoluted shape that offsetting the distance you want to go will cause problems. You need to simplify the design in those areas.


you can convert it to mesh, then use the command mentioned by pascal Offset Mesh and convert it back to nurbs with the command MeshToNURB if you want.
fox help_.3dm (5.7 MB)


Thank you SO much! This worked! I have a watertight solid!