Replace Z value with current elevation doesn't work with grips

I have googled multiple forums over several years and never found a similar post. So I had to join and ask the question. I am a surveyor and I work with point files. I have to generate 3d surfaces but I have to have 2d linework. Every morning first thing I do is go to options and click Replace Z value with current elevation so my linework doesn't carry an elevation. If I draw a line from point node to point node it works fine, the line will have no elevation. But if I draw a line in space, grab it by it's grip, and snap it to a point, the line with carry the elevation regardless of whether the replace Z value box has been checked. Does anyone know how to make this stop?

Use stretch command instead of grips or lwpolyline instead of line. You could draw the lines in paper space snapping to objects in a viewport, then use chspace to move it to model space. Snapping that way never gets elevation.

Try in Osnaps turn off the 3d object snap Node.

As a fellow surveyor what software are you using for surfaces & contours? I've been spoiled on Civil 3D, but have used Eagle Point in the past.

I used to use a point filter macro Z;0 that would assign elevation 0 so you would only get the XY from what you snapped to. Off today, but I could post it later this week. I put the macro in with my osnap menu.

For some reason, when I put a line in paper space and do a change space command it DOES change the elevation

For some reason, when I put a line in paper space and do a change space command it DOES change the elevation

While I haven't seen it change the elevation myself others online blame it on either a UCS elevation assigned or a corrupt viewport issue.

http://forums.autodesk.com/t5/autocad-2007-2008-2009/chspace-changing-elevation/m-p/3036740#M143310

I did not think of that. I will check out the link. Thanks tombu

Did you ever manage to figure out the answer?

I"m having this exact same issue in my linework.

I was excited when I found out OSNAPZ as I figured it would fix all my problems, but as I started working with it, I noticed Z - coordinates kept creeping in... After experimenting with the lines, I realized that new lines were set to elevation 0, but that stretching an existing line by the grips was causing the issue.

Using the STRETCH does not cause the same problem, but its super cumbersome, I don't see it as a viable alternative to grips.

Grips have nothing to do with Object Snap settings. Using grips works the same with Object Snaps turned off as they do with them turned on. OSNAPZ only applies when using object snaps. Instead of picking a grip to stretch to hold the cursor over the line close enough to see it's stretching where you want it with your Object Snap settings and click. That way honors the OSNAPZ setting.

Easy-peazy!