Finite element model of a mouse (2D elements). Left: Original mesh; Middle: Offset mesh; Right: Original and offset mesh (via overlay) |

1) Equivalence your surface mesh (remove duplicated nodes).

2) Calculate the smooth node normals:

--Calculate the element (face) normals.

--Add the element normal to every node that is shared by the element.

3) Normalize the normals at the nodes (unit vectors, pointing away from the surface).

4) Multiply the normal vectors with the desired offset.

The results of this procedure can be seen in the image above.

If anybody is interested in the code (written Pyton) I can send it via email.