How to thin a face mask

[Anonymous]

Hello, I'm trying with all tricks to thin the model of a face mask, to make it printable.

I tried to group faces and than extrude negative. Also I created a dublicate and then tried to substract.

All didn't work.

Any suggestions, what to do?

It is this mask from thingiverse:

https://www.thingiverse.com/thing:515615

Thanks a lot!

[MagWeb · Accepted solution]

GenerateFaceGroups at Mode=EdgeAngle, AngleThreshhold at 53 and SizeThreshold at 50 gives a single face group for the front of this mask.

In SELECT select this group by double click.

Hit I to invert the selection and X to discard the mask's back.

Again select the front group and run Edit/Offset to build a new thickness (Note: You might need to set the output size first in ANALYSIS/UnitsDimension)

[Anonymous]

Thanks a lot, that worked easy after your instructions.

Could you please advice me shortly how to export it really smooth. When I export it as an stl or obj it gets quite edgy, as it doesn't have enogh polygons. How can I change the quality?

[MagWeb]

I would do such refinement on the front only (file size reasons).

So after you set the new thickness select the front surface again and run Edit/Remesh. Set RemeshMode to RelativeDensity and make sure that BoundaryMode is at FixedBoundary. Now rise Density to its max. 

Accept and run Deform/Smooth on that selection too.

If you still need more triangles repeat the process.