Autodesk Design Review measures accurately regardless of line weight

A Mr. Richard Feder from Fort Lee, New Jersey writes in an asks:

When measuring with Autodesk Design Review, what am I measuring? Am I measuring what appears in paper space or am I measuring what was created in model space?

A DWF is an information model. When you measure, you are actually measuring the entities used to create that model. Autodesk Design Review is viewport aware, so it takes into account the scale of the viewport -- even in paper space. I was curious if line weights, which are really just a representation of the object in paper space, would impact the measurement calculations.

To test this, I created a simple DWG that had two squares. One had a default line weight of 0.25 mm. The other had a line weight of 2.0 millimeters.

I then published Layout1 to a DWF file.

When I measured the areas using Autodesk Design Review, I got matching area measurement results. Each 4 by 4 square measured as 16 units.

Autodesk Design Review used the dimensions of the objects as inserted in model space, not the "area of the paper" occupied by these objects in paper space. This is as it should be when you have an information model instead of a picture of a model.