Hi Eric - the Network command needs to have its input curves arranged in a particular manner, it is not able to just take any set of curves and use them.

In your topo.3dm file the curves are arranged in the right way for Network to process them, which is in a grid like manner where you have 2 sets of curves that can be identified similar to latitude and longitude lines on a world map.

Network must have a regular grid layout like that to work.

Your new curves are arranged like this:



As you can see those curves have no relation to latitude / longitude lines on map, they are not organized into a regular grid pattern like that, so they are not suitable for input for Network.

Something like that can work better with a surface fitting mechanism like Rhino's Patch. MoI does not currently have an equivalent command to that, so for now you will need to use Rhino to create that kind of a surface.

- Michael