Creating a surface In Revit 2010 from a linked AutoCAD DWG containing vertical lines

I thought I’d share this trick with you. This approach is particularly useful if you are trying to create a complex surface. The idea is to create a series of vertical lines, in the z axis in AutoCAD, spaced evenly with varying lengths. Link the resulting DWG into Revit and then using the new massing tools in Revit 2010, build a surface using points and splines attached to vertical z axis lines on the linked DWG.