I am working on contours i have x,y value i want to convert in 3D How i convert 2D to 3D without wastage of time please help me Thanks.

You mean you have contours placed in 2D only (Z=0) and you want to elevate them to their altitudes? The CHELEV Lisp utility may help you in this case - see the tip:
http://www.cadforum.cz/cadforum/qaID.asp?tip=5791
(in Czech but the sample DWG and CHELEV.LSP is there)

thanks but this tip is any other language

TYPE   EXT IN THE COMMAND BOX
SELECT THE OBJECT YOU WANT TO CONVERT 2D INTO 3D
GIVE THE HIGHT TO  DESIRED
PRESS ENTER.
GIVE THE ANGLE IF YOU NEED OR LEAVE IT . AND PRESS ENTER
GO TO VIEW MENUE
CLICK ON VIEWPORTS AND THEN CLICK ON EITHER (SW, WE, NS ETC)
THIS THIS HOW YOU CONVERT 2D TO 3D .

Thanks Malik-Noor

Hi tariqGeneraly in Autocad convert 3d object in to 2d. your query is unique. any way you use following product http://www.hexacad.com/download.phpformHexagon

The HEXACAD is a complete CAD Software with features like 3D Modeling,
database connectivity, built in Script support, customized report
generation, walk through creation, animation, voice enabled interactive
demo creation and many more. This software is compatible with AutoCAD
dxf (Drawing Exchange Format) files and up to dwg 2000 file format.
Currently hexacad is available on the site with HVAC vertical.
Application is developed in VC++ using technologies like OpenGL, ODBC,
SAPI, internet, automation etc. Features of the system

3D Modeling: The System supports 3D Modeling representation
of any three-dimensional object (either inanimate or living) .
Data Base Connectivity: Records are stored in Data Bases.

Scripting Support: Providing Built in Support for any time of Scripting.

Customized report generation: All Formatted Report is generated.



Animation: System supports Animation provide better looks.

Voice enabled interaction: System Provide Voice Interaction for Demo for Presentation.
Compatibility: Compatible with various format including Dxf and dwg 2000 file format.