CAD Overlay 2001i

Autodesk's CAD Overlay 2000i is unique because it's the only one of the five that doesn't offer fully automatic vectorization tools.

Autodesk, Inc.
AutoCAD-Based
5 stars out of 5
800.964.6432

With Autodesk CAD Overlay 2000i, you can use bitonal filters for image processing. This Bitonal Features dialog box thins, thickens, and smooths raster entities.

Autodesk's CAD Overlay 2000i ($1,395) is unique because it's the only one of the five that doesn't offer fully automatic vectorization tools. Autodesk recoded CAD Overlay's vector kernel and introduced two new classes of tools. Primitives let you interactively convert raster geometry to AutoCAD primitives while controlling options such as raster erasure and vector separation. Followers let you semiautomatically convert scanned contour and soils maps.

With interactive vectorization, instead of feeding a scanned image into your software, you use drawing commands to construct a CAD model from the image. This sounds like work, but it has advantages. You convert only what you want, control layering, use your own blocks and text, and verify your drawing as you create it by entering specified dimensions rather than accepting the results of automated vectorization. What time you lose, you often make up by not having to clean up the converted file later.

CAD Overlay features a line-following semiautomatic function ideal for converting irregular shapes such as contour lines. As you pick the raster data, the software automatically follows it and creates AutoCAD lines and polylines. If you use one of Autodesk's Desktop products, CAD Overlay offers features that are Desktop-specific. For example, in Land Development Desktop, when you convert a file, you can bring in the raster lines as contour objects.

My only complaint is that I'd like to easily remove CAD Overlay's menus and toolbars from my AutoCAD interface—they reload each time you start AutoCAD.

CAD Overlay comes with a 160-page manual and six tutorials. It's a solid contender, and I know service bureaus that prefer it over automatic programs. CAD Overlay 2002, a port to AutoCAD 2002, should be available by June 15. Highly Recommended.