3D Tunnel Model

[OceanaPolynom]

Hello
I need to create a 3D Model of a tunnel in AutoCad. I think that the tunnel should be made of 1 or more surfaces, and that a 3D polyline should be the center line of the tunnel. The 3D pline should be composed of lines and arcs, with the arcs tangential to the lines, like the center line of a road.
I also need to determine the shortest distance between any x y z point inside the tunnel model, and the nearest wall (surface) of the model.
I have experimented with SWEEP using a straight 3D pline and a semi-circle. The first problem is that snap to nearest does not work as expected on the swept surface, it only snaps to certain lines on the surface. The second problem is that I don't know if it is possible to create a 3D polyline as described, like a road centerline.

Is what I need to do even possible in AutoCad, or do I need Civil 3D?

Thank you
John

[AllenJessup]

Google 'Civil 3D Tunnel'. There are blogs and video describing how to use Corridors and Assemblies to create a tunnel.

Allen

[OceanaPolynom]

Thanks for the advice

John

[OceanaPolynom]

After looking around I found many references to these posts:

http://civilcommunity.autodesk.com/blogs/blog/6/blogpost/3758/
http://civilcommunity.autodesk.com/blogs/blog/6/blogpost/3724/
http://civilcommunity.autodesk.com/blogs/blog/6/blogpost/3716/

but I cannot find them.  Do they still exist?  How can I read them?

Thank you

John

[AllenJessup]

Try

Intersection Assembly Sets for Tunnels

Tunnel Cross Section

Tunnel Cross Section2

Can't vouch for their efectivness. But they're there.

Allen

[OceanaPolynom]

Thanks again

John