CAD Overlay CAD Overlay CAD Overlay is a commercial software application for raster-to-vector translation in 2D computer-aided design (CAD) and drafting — available between 1988 and 1996 as a third-party application for AutoCAD and other CAD systems. Developed and marketed by Image Systems Technology, CAD Overlay was first released in January 1988 running on AutoCAD Version 2.6. CAD Overlay replaced the previous generation of automatic raster-to-vector translation systems by embedding scanned documents and images directly in the CAD system. CAD Overlay was derived from a custom AutoCAD application developed using the Nth Engine graphics board in 1987 by David Chassin for Image
CAD data exchange of describing geometry, both mathematically and structurally, there is always some loss of information when translating data from one CAD data format to another. One example is when the translation occurs between CAD systems using different geometric modeling kernels, in which the translation inconsistencies can lead to anomalies in the data. The intermediate file formats are also limited in what they can describe, and they can be interpreted differently by both the sending and receiving systems. It is, therefore, important when transferring data between systems to identify what needs to be translated. If only the 3D model is required for