Trace a Spline in a Linked Dwg File and Some Recommended Reading

The scenario. You get a dwg file for overlay. The architect has drawn a beautiful sweeping curved  edge to their building, You link the dwg file into your model and see its a Spline.

Which presents two problems:

• You can't trace over it in Revit
• You can't set it out. And if you can't draw it, they can't build it

Fortunately, you can use the 'Flatten' command in Autocad to turn it to a polyline of arcs. By then exploding the polyline, you are left with a series of arcs that you can pick in Revit and also set out. The following short video demonstrates this



On another note and as a supplement to this, I recently came across
'The CAD Setter Out' blog by Paul Munford. For people who regularly have to clean up third party CAD files for use in Revit (or generally), this is comprehensive and highly useful resource. Its written generally from the CNC/Fabrication perspective, but is very pertinent reading to the designer. I'd recommend the following posts as a starter

From CAD to CAM, Cleaning up 2D DWG files for CNC.

How to optimize your AutoCAD DWG drawing files

Why Setter Outs aren’t (and don’t want to be) Designers.