Warning: DWF Files Can Be Measured

While we are on the topic of Autodesk Inventor, there was a recent discussion.autodesk.com thread in the autodesk.inventor newsgroup regarding DWF files and their ability to be measured.

For 2D measurement, Autodesk Design Review provides a length tool, a polyline tool, and an area tool.

• The length tool measures the distance between two points. Because DWF files retain the intelligence of the original design, measurements can be taken by snapping to appropriate shapes.
• The polyline tool measures the cumulative length of multiple polyline segments, including rectangles.
• The area tool measures the area of a polygon or rectangle.

For 3D, Autodesk Design Review can measure:

• distances between points, edges, center points, or any combination of these,
• angles between edges, and
• radii of circles and arcs.

Autodesk Inventor produces very precise DWF files that can be accurately measured. Although some discussion group members felt that additional information may be required, others felt that the combination of rich metadata (such as material properties) and the ability to accurately measure, could allow an unscrupulous person to reverse engineer a product from a DWF file. They felt that DWF files should be posted to the general public with this in mind. Autodesk is working with its customers on ways to allow or disallow measurement for specific DWF files.

A DWF file is an artifact of the design process. It is certainly not as intellectually rich as original 3D part model or 3D assembly model data with constraints and interrelationships among the components. On the other hand, a DWF file is certainly richer than something like a plot file. Even so, given an adequate set of plans on paper, products can be reverse engineered. Thus it is important to safeguard intellectual property regardless of its form. Autodesk Inventor R11 DWF Extension, available to Autodesk Inventor subscription customers, provides the ability to create a measurement-disabled DWF. Autodesk Design Review 2007 honors the disablement.