Locking cursor to z-value '0' when snapping to 3D points

Apparently you can draw 2D lines in Microstation and even snap to 3D points while still keeping your cursor to x,y,0.

They "lock" the cursor to z-value '0'.

Is this possible in AutoCAD?

Change the OSnapZ variable to 1.

Okay - thank you - that has helped, however, the cursor now doesn't snap to anything that isn't on level 0. So, is there a way in which it could still snap to 3D points whilst remaining in 2D? It may sound odd, but like I said, this is something they apparently do in Microstation, so of course AutoCAD must be able to do the same ;-)

It should still snap to non zero elevation points, it just won't extract the elevation. Are you working with extruded objects?

No, not really, these are 3D objects (some inserted and some created in AutoCAD). I did just try it with an extruded object and it only snaps to the points in 0, not the extruded part.

No, not really, these are 3D objects (some inserted and some created in AutoCAD). I did just try it with an extruded object and it only snaps to the points in 0, not the extruded part.

Ehh, little out of my league. I work in civil 3d, which has 3d objects, but they dont' function the same as regular ones.

I fear this may be a situation where you have to just toggle the variable.

You could use this as a OSnapZ toggle:

(defun c:test (/) (setvar 'OSNAPZ (abs (1- (getvar 'OSNAPZ)))) (princ))

Thanks, I will try that - you have helped a lot!!

Thanks, I will try that - you have helped a lot!!

No problem. If you do decide to use the command, you can easily change the command name by replacing "test" with whatever you like. I'd pick something short.

If you assign this to a button, be sure to put an apostrophe ' in front of the command so it can be executed transparently.

If alanjt's solution doesn't do it for you, then try this option on the drafting tab of your OPTIONS.

If alanjt's solution doesn't do it for you, then try this option on the drafting tab of your OPTIONS.

Same effect. All three deal with the OSNAPZ system variable.

See I WISH EVERYTHING WERE FLAT at Cadalyst.