Extruding along a path AND tapering/changing X-sectional shape ?

Hi !

I'm using ACAD 2002, and would like to extrude some polygons and
circles along a path, and get them to taper along the path. I can
create tapered extrusions from 2D objects in the z-plane, but there
doesn't seem to be the option to taper extruded 2D objects along a
path. Is there any way to do this?

Also (getting more creative !) I'd like to extrude along a path
between two different 2D objects - e.g a circle and an elipse - so
that I get a curved pipe which is initially circular in cross section,
morphing into an eliptical cross section at the other end. Maybe
there's a LISP routine out there that can do this ?

Finally, I know that loads of people have written interesting LISP
routines to create new and useful AutoCAD tools. Is there a good web
archive where I can look for downloadable LISP routines with
descriptions and instructions ?

Many thanks in anticipation

Dave

 

HiHo;
Rhino from www.mcneel.com is very good at extruding along one, two paths
(rails)
and a free demo is available.

 

Thanks for the suggestion. Would like to do it all using AutoCAD
routines if possible (not enough time or money to learn new CAD
package !)

Best wishes

Dave