I have CAD files from AutoCAD and from MicroStation. I need to know if it's 2D or 3D. I have FME at my disposal. How can I know if it's 2D or 3D in FME?
There is a thread on the Safe Software forums which asks the same question, with a response that suggests the following:
Visual check - view data in Inspector in 3d - view data edge on (ie in elevation). You will see a long horizontal line if data is in 2d - otherwise it's in 3d (or badly drawn 2d !!!)
Expose X,Y and Z attributes of all data. Test for any Z attribute not equal to 0 - if any Z attributes are not equal to 0 - data is probably 3d. Strictly speaking, test to see if all data (nodes / vertices) have the same Z value. Use a Statistics Calculator and a GroupBy on the Z attribute. If you have 1 Z value (probably 0) - data is 2d If you have >1 Z value - data is 3d or badly drawn 2d - see visual check above.
There is more information on that thread that may be of use to you as well.