Transforms the solid into a thin-walled solid shell by offsetting faces. 

eOk if successful or an appropriate error code in other case.

Offset can have an outside or inside direction related to the solid, depending on the sign of the offsetDistance parameter:

• positive value means outside direction;
• negative value means inside direction.

If a face has surfaces that cannot be offset by the thickness, it will be removed from the solid. Removal wound is healed with the surrounding face surfaces. Edges and vertices on the specified faces will be merged if possible. Isolated edges in tweaked faces and neighboring faces may degenerate to points and will be removed. However, when removing loops or faces, insertion of edges or other topology changes are prohibited. Operation can cause the solid to become invalid in some cases. This method is implemented only for Spatial modeler and returns the eNotImplementedYet status for other modelers.