ZEMAX models most optical components using parametric surfaces and objects. However, sometimes you need to trace rays through arbitrary shaped objects defined in mechanical CAD programs like ProEngineer, AutoCAD, SolidWorks and others.

ZEMAX supports the following CAD standards:

Imports:	Radial NURBS, Toroidal NURBS (as sequential surfaces) IGES, SAT, STEP and STL (as non-sequential objects)
Exports:	IGES, STEP, SAT, STL and BDF objects (sequential and non-sequential)

2D and 3D DXF formats are also supported from a seperate tool.

Imported CAD objects can be prescribed coating and scattering functions that vary over the surface of the object, and several faces with shared properties can be grouped together.