Expert: Bill DeShawn - 5/5/2010

Question
QUESTION: Hi Mr. Bill,

I needed to know if there is any way to find out if a DWG file is a 2D or 3D. I tried accessing each individual entity and checking the AEC type, but that was cumbersome.

Thanks.

Padman S.

ANSWER: Padman:
One quick way that I do it is to be in the Model tab and use the 3DORBIT command to visually check if everything is on the same plane or not.  If it's 3D, some things will start "flying" faster than others.  :-)  I do this all the time in civil drawings that have contours.  Afterwards you can use the Plan command and the Current UCS option to put things back to normal.

Let me know how it goes.

Bill DeShawn


---------- FOLLOW-UP ----------

QUESTION: Hello Mr. Bill,

I appreciate your reply. I actually needed to distinguish 2D/3D DWGs not visually , but through some other way that represents a 3D/2D file uniquely( eg. command, system variable etc.)in the DWG file itself. It will be helpful if you could shed some light in this respect.

Thanks again.

Padman S.

Answer
I haven't reviewed AutoCAD 2011 yet, but through 2010 there is no version of AutoCAD that has a core command or system variable that will tell the user whether there are any objects drawn with any part of them at an elevation other than zero while in the WORLD UCS; or if there are any 3D solids, faces or meshes in the drawing.  There could be LISP routines available somewhere that will do that, even I could write one.  :-)  But not today.  

You could use the SSX.lsp or QSELECT to see if there are any 3DSOLIDS in the drawing.  Not sure what to suggest 'cause I don't know what discipline you draw for.