i guess you can use the LOFT command, although you might encounter some problems with curve directions depending upon how the plines were generated.

ret is right... if you dont draw all the plines the same direction in cad, the normals will be flipped and the loft command will come out all funky

but loft is the command i would recomend... just make sure you draw all the plines in the same direction

... you dont have to redraw the curves - just use the "dir" command to make all the curves have the same direction...

Loft didn't work for me because it generates too much curvature in the surface. I used the patche command because it easier to control, but if you're terrain is too complex (too much contours lines) rhino will crash. The most efficient way is, as usual the longest: create a highly subdivided planar surface and pull the point to you contour lines. Another method if you're not looking for accuracy and if you plan to render it is to model it in max with the terrain modifier. or you can create a displacement map from an eps print of your contour lines in cad and use it with the displacement modifier...
there's no good solution for that I'm afraid. The most accurate is such a pain in the ass to do...

Here is how you do it.

First there is a rhino plug in called terrain: download the trial version.

next import your autocad plines.

use the divide command to divide the plines into points (set a point distance, do not use # of points)

type terrain (plug in comand)

select points

this will generate your mesh....

important to not, this is not a surface, or polysurface....just a triangulated mesh

French ur right it's just a pain in the but, but thanks, and Syl ur right it worked with the dir! Thank U guys!

by the way, your contours need to be located in 3d space in order for this to work.

Hey NeilD can i do it in the rhino web site!? Thanx

there are a number of sites to download the plugin...
google search: rhino terrain plug in
most offer a free demo.

how about network surface commant in rhino ??

How about try it in sketchup then send it to rhino and render it?
In sketchup you can import you auto cad file, then go to preferences click on extensions then choose sandbox. The sandbox tools are very easy from there you can export it to Rhino.
If you don't have sketchup then you can download it for free and use it for 8 hours.
good luck!

just use the drape command. i think.

The easy way (this only works if your contours are all closed plines) is to place each contour line at the elevation it is supposed ot represent, then select all of them and use the PATCH command.. it will place a surface on youre lines that hits each contour. Usually works well. PATCH is a tool button in the Surface Tools menu.

U 've been very helpful DUDES THANX!!!

Hotsie, the trick is good but, mate i have 5sq/km of broken plines!!U can imagine...

cant u just join all of them?

if your site is in the US, just buy a terrain DXF..and use the drape command in rhino to create a NURBS surface if that is what you desire.
if you want i will check my emails for the URL where you can buy this stuff, i did it onece a few months ago. Quick and Easy

Ret, my territory of action is in Thailand, the guys from there sent me in dwg, but if ur saying that i can use the drape with dxf, i'll just try it. thanx!

is this for the design competition?

Yuup! Since we're a little bit late, i've been doing all the 2d stuff first! Are u in the competition as well?

thought i saw it a few days ago...i'm not participating,no.