Autodesk Labs just released the Technology Preview for the Civil 3D Corridor Sub-Assembly Composer that should prove to make life substantially less aggravating for those of us that need some customized structures in our models. For me, the most notable issue has been has been retaining walls, but some customization of basic structures has caused no shortage of discomfort either.
The interface provides point definition, link information and sequencing. Once complete, just write out the .pkt file, and import the Sub-Assembly into Civil 3D.
Here’s a pic where the Corridor was rebuild after the new curb was completed.
Conditions can be evaluated in two forms: Cut/Fill, and General Statements. The image below represents one of the Autodesk Labs examples where both a Cut/Fill condition and a Basin True False (General) condition are evaluated.
A very simple flow chart interface is employed to make sense of the operation. This is a nice addition, that will slide in very nicely to 2012 (I hope).