Shape Merge

Shape Merge command is used to embed shapes in a mesh surface or to cut shapes out of it . The faces, vertices and edges created by embedded shapes are automatically selected at the sub object level so that you can easily extrude, bevel or assign material to them.

To perform a ShapeMerge Operation:-

Position a shape  over the surface of a mesh object.

Select the mesh object.

Open the Create Panel & choose Geometry-- Compound Objects--ShapeMerge

Choose a clone type & click Pick Shape, then click the shape.

The shape is embedded in the surface of the mesh.

Choose Cookie Cutter to cut the area enclosed by the shape out of the mesh surface. 

Check Invert to cut the surface away from the embedded shape area.

Choose Merge to embed the shape with the object(Convert it into Editable poly, select its face and extrude)