my current modus operandi is to draw it in autocad and then import to sketchup which has significantly better rendering, coloring, transparency,
and which does perspective- which my version of autocad doesn't.
I hear about blender now and then- must admit i can't afford anything -t the version of autocad i have is a discontinued 1998 version or some such that the old owner had replaced and no longer needed.
But the combination works really well- i mean sketchup is whacky in terms
of trying to do anything with exactness. Theres no array function. You can't
zoom "down" into scale, just upwardor through the object. I mean sketchup is frankly lousy at actually drawing things in. But its great for file sharing,
its free, i can get freinds to go get it and maybe they can do stuff-
Until i make big dough i am afraid thats where its at for me.
But hey, still makes allright stuff- not as kewl looking as some of the art i see- but nothing to scoff at neither.
that bridge design does look pretty detailed--- WOW...