Offset is a surfacing tool which proportionally displaces all dimensions of an entire face part by a specified distance. Offset works in the same way as the Thicken tool, but the original faces are not kept and connecting surfaces are not created.

You can specify a positive offset or negative offset. A positive value offsets all faces of the face part in the face normal direction.

Two methods are available to calculate the size of the offset curves at the borders between adjacent faces. The default method (Ortho) uses the intersection between offset surfaces and the surface at right-angles (orthogonal) to the original edge. This method may occasionally result in the generation of undesirable edges, especially when offsetting triangular faces like that shown in the figure. An alternative method, to prevent the generation of these correct but undesirable edges, creates the offset curves so that they meet exactly at the vertices where two open edges meet.

The figure compares an offset operation on the same face part using the default orthogonal method (1) and the alternative (2). The edge generated by an orthogonal offset (3) is not created by the alternative offset method. Instead, the vertex (4) is fixed as the point at which the two open edges meet. Both the original and offset face parts are shown for clarity.

Blended edges in the original face part are not kept as blends in the offset face part; they are considered as generic faces, and cannot be modified as blends.