Losing Z-values when exploding blocks. Help!

[danimalvt]

I am trying to convert contours created in ArcView 9.1/8.x to CAD polyline entities while retaining the Z-value for each contour polyline. I create the contours in ArcView 9.1. I add a new field "Elevation", type double, so that AutoCAD will recognize the values and not simply dump everything. Next I export them using the Shape to DXF tool from version 8.x (in ArcCatalog).

When I open the DXF in AutoCAD (Land Desktop 2004), I get an error message regarding 3D values in 2D polylines and am told to run Audit. This takes care of the error. However, the contours in the DXF are read by AutoCAD as Blocks, which must be exploded in order to be manipulated. When I explode the blocks, they disappear...completely. I cannot even use "Undo" to get them back!

Attempts at another process have been futile. I can get the contours in but the Z-values are always "0". Since I am dealing with thousands of individual polylines, it is not practical to set the attribute for each contour.

Please help! Any workable suggestions would be appreciated.

Thanks!

Dan

[CarlB]

Can you open the DXF file in a word processor, and do some kind of global search and replace to remove the z value from the vertex data before bringing it in to AutoCAD? You might make a simple polyline drawing in AutoCAD, create a DXF, and look at the file to see what the polyline DXF information *should* look like.