By Dennis Collin
Quite often several of the following symptoms may result after importing or working with a Land Surveyors' or Civil Engineering drawing;
Trim/Extend and Fillet and Chamfer commands don't work
Hatching, Bpoly and Area commands fail to detect boundary objects and work.
'Object is not Co-planar to current UCS ' error message
Text using true type fonts seem excessively bold
This may be due to drawn 2d elements snapping to 3d entities (like contours) with a set height! This can easily be checked by using the view cube tool and look at the drawing from the side or check the offending elements and see if they have any Delta Z values in their properties (change to zero) Or alternatively use the Flatten tool that comes with the Express tools (this is not available for AutoCAD LT!) You might also want to use the Quick Select tool to quickly check and ensure the objects you are editing need the same zero 'z' elevation or height.
Offending drawing in PLAN and ................in an elevation view (Use DDVPoint or ViewCube) NB the slanted line!
To prevent the problem happening again (in both full and LT AutoCAD), check the options dialogue, click on the drafting tab as shown below and tick ' Replace Z Value with Current Elevation' (normally zero) This should force all newly drawn objects to be flat and accept 2d editing commands.