Drawing flat (Z=0) polylines to point xy coordinates in Civil 3d

[mcloughlin]

In old LDD, points inserted at Z=0, so that when one drew a boundary polyline point-to-point, this line sat at Z=0 at all of its apices. 

In Civil 3D, points insert at stated elevation, and a boundary polyline is no longer flat, but a 3D polyline with wildly varying segment lengths, etc. 

How does one simply draw a polyline snapping to points, but at Z=0?  One cannot simply flatten a 3D polyline, because its apices move from the point xy coordinates when each apex moves to Z=0, and if one attempts to drag the new apex back to the point, voila! it returns to the original Z value, in our particular Rocky Mountain case greater than 7,000 feet, so that segments of a small parcel become greater than a mile in length, etc.. 

We need to expeditiously connect points with a polyline on a flat Z=0 plane.  How do we do this?

Thanks!

[stacy.dunn]

You can change the point style so that the marker is represented in cad at a zero elevation.  The points will retain their elevation data, but are drawn at the elevation specified.

[Jeff_M]

In addition to Stacy's suggestion, you could also set OSNAPZ to 1 which prevents snapping to the Z value of the node.

[doni49]

In addition to the other comments offered, if you are drawing a polyline, (type in PL) then you ARE drawing a 2d polyline.  If you want a 3d polyline, you have to explicity say so by typing 3dpoly (or choosing it from the Ribbon or a menu somewhere).  A 2d pline is drawn all at one elevation -- that of the first point selected.

So if you don't want to use the other suggestions (such as a one-off line and you don't want to change the setting(s) for one pline), then you could:

1. Start your pline.
2. When you're selecting your first point, Shift+right-click>Point Filter>XY
3. Choose your first point.
4. You will be prompted for a z value, type 0.
5. The remainder of the pline will be also be at 0.

Of course, other elements (lines, arcs etc) will most certainly look to use the elevation of the chosen point.