ABSTRACT
In the extrude operation, a 2-D object in plan projection can be extruded to a specified height value. If the 2-D object was drawn in elevation, then the extrusion will determine the depth value. In some CAD systems, this operation is described as constructing a surface projection rather than extrusion, since volumetric objects are created by projecting a 2-D surface through 3-D space. Extruding 2-D objects. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315042794/9ea7e050-bfcd-4e93-9c13-6f9a9d99f4d1/content/fig13_1_C.jpg" xmlns:xlink="https://www.w3.org/1999/xlink"/>
