Q) I have a DWG file with LWPolylines in it. Why do they show up in MSCAD but I can’t seem to extract data from them to create a surface?

A) MSCAD knows what a LWPolyline is, for CAD purposes, and can draw it to your screen. However, we do not currently have the ability to extract data from them (like we do with normal polylines), to allow you to generate a surface. You could ask your source to save their drawing to R12 DWG format and the LWPolylines will then be converted to normal Polylines.