Organic mesh to thin solid - need a workflow

[jschrempp]

I'm trying to make a 3mm thin mask from a scan of a head that I can 3D print - like a Mardi Gras mask. I have tried and failed to do this in many ways. With the mesh I've made a copy at 95% of the original, positioned behind the original with the intent to then combine them into one mesh. I couldn't find a way to do that.  I converted the mesh to a surface and tried Thicken, but that gave errors. I converted the mesh to a BREP and tried Shell, but that gave errors. After watching some tutorial videos I tried to use Create Mesh Section Sketch and use them to create some BREP parts that I could then degrade to a mesh and combine with the existing, but I failed to find a workflow that worked.

I have done a brute force on this by creating the BREP and then cutting out sections of it with Loft to get a kind of workable solution, but it is so inelegant. It's like a face on the outside of a cylinder, not really a mask at all.

I'm at a loss on how to proceed with this. Any ideas are appreciated. I feel that I must be missing some key understanding here.

I'll attach my sample file to this post.

Jim

[TrippyLighting · Accepted solution]

Convert the original mesh into a .obj file (I used Meshmixer).

Open in Instant Meshes and follow the workflow described here.

I used about 2000 faces, align to boundary and saved as pure quad mesh with 2 smoothing iterations.

Enjoy the results:

 

[jhackney1972]

Here is a 3mm thicken model to the outside.

[TrippyLighting]

@jhackney1972

I am surprised that this converts using the prismatic mesh conversion. There's noting prismatic about this mesh 😉

Very cool though and worth a try!

[hfcandrew]

...and as usual here's Andrew a bit late to the party with the usual advice of: If you have a triangulated mesh (.stl) then use Meshmixer.

Just two clicks, go Edit>Offset

https://help.autodesk.com/view/MSHMXR/2019/ENU/?guid=GUID-749E6C72-D82B-4FA9-A157-1AE612B779AE

The result will be solid (meaning watertight/printable).

[jschrempp]

Thank you sooo much! That video of the workflow was just what I needed. 

I applied it to the entire head and got what I needed.

The only problem I ran into was converting the TSpline into BREP. I ended up having to do a repair, export the model, then import it and repair it again. That changed the error into "intersecting surface" error. Repair Body would not fix it.

After a long period of massive frustration (and a few Fusion 360 crashes), I had a hunch that the problem would be at the bottom boundary of my model. I zoomed in closely and followed the edge around looking for issues. I deleted some faces and filled them in, still no luck. Then I decided to try Repair Body again. I happened to be zoomed way, way, way in on my model and surprise, there was a little red star on the model that did not show up when zoomed out. I guess some underlying problem with Fusion360 display? A bit of deleting around that area and then Repair Body worked!!! And now I have a model. 

Thank you again very much.