Welcome to Autodesk’s Meshmixer Forums. Share your knowledge, ask questions, and explore popular Meshmixer topics.
Showing results for 
Show  only  | Search instead for 
Did you mean: 

thicken surface towards outside direction

Message 1 of 5
1199 Views, 4 Replies

thicken surface towards outside direction

Hi everyone,

I was trying to thicken the surface of a hollow model towards outside direction by selecting outside surface and then extruding it. But every time I selected with brush, the inside part was always included by default. Does anyone have any idea on how to manage that? 

Thank you so much!

Message 2 of 5
in reply to: Anonymous

You're using The Sphere BrushMode > anything inside a brush's sphere is selected.


From MM Help:

"There are three Brush Modes:

  • Unwrap mode selects a highlighted, connected patch of the surface around the brush.
  • Sphere mode replaces the grey patch with a semitransparent Sphere, and selects everything inside the sphere. The key thing with Sphere mode is that you can select disconnected regions, so it is good if you are selecting in areas where there are lots of disconnected meshes.
  • SphereDisc mode is a sort of hybrid, that uses a Sphere but limits the selection to those faces that are connected (via some path on the 3D surface) to the point under the cursor. "

The Unwrap mode should do it:


To thicken a selected region Edit/Offset (with Connected checked and SoftTransition set to some value bigger than zero) is the proper tool:


Gunter Weber
Triangle Artisan

Message 3 of 5
in reply to: MagWeb

Thank you so much! It works very well! Would you mind explaining a bit more on why "offset" instead of "extrude-normal" to do thickening?

Message 4 of 5
in reply to: Anonymous

If you want to thicken a convex surface Extrude in Normal Direction gives the same result as a connected Offset with zero transition. One difference is that Offset allows to define a Transition from the source level to the offset level. Against that Extrude will result in a harsh stair (Which needs to be smoothed out later.


On a concave region selected Extrude might run into self intersections:

E.g This selection

Ohne Titel 2.jpeg

results in this Extrusion result (cut to show the self intersection):

Ohne Titel.jpeg

Against that Offset tries to solve those self intersections:

Ohne Titel 3.jpeg

Gunter Weber
Triangle Artisan

Message 5 of 5
in reply to: MagWeb

Thank you! That's very helpful!

Can't find what you're looking for? Ask the community or share your knowledge.

Post to forums