THis is not easy, but what seems to work best is fitting tensioned splines. See the following reference:
Goodwillie, A. M., Producing Gridded Databases directly from Contour Maps, Tech Report, University of California, San Diego, Scripps Institution of Oceanography, La Jolla, CA, SIO Reference Series No. 96-17, 33 pp., 1996. ~ If your library cannot get this, contact Andrew Goodwillie at Northern Arizona Univ. lmd > Delivered-To: [EMAIL PROTECTED] > X-Originating-IP: [207.34.94.238] > Mime-Version: 1.0 > X-OriginalArrivalTime: 11 Jan 2002 20:35:51.0047 (UTC) FILETIME=[8EFDD970:01C19ADF] > Date: Fri, 11 Jan 2002 13:35:50 -0700 > From: gaoming fu <[EMAIL PROTECTED]> > Subject: [JAVA3D] converting contour lines to grids > To: [EMAIL PROTECTED] > Hello, All I need help for converting contour lines to grids. My original data are contour lines in an area of 1 mile by 1 mile. Each contour line consists of some points, each point has x, y, and z. There are totally about 1000 points. My data file is something like the following: 12.3 23.6 60 17.6 47.9 60 35.9 68.0 60 . . . 234 567 120 250 345 120 . . . Each line is the x, y and z value of one line. Now I want to draw the topography surface. I did the following: 1. Set the grid size (e.g., 10 m) 2. Find the x and y of the grid points (e.g., (0, 0), (10, 0), ...) 3. Interpolate these grid points to get their z values 4. Draw the grid points to get the topography surface I tried methods of moving average, weighted average, and nearest neighbor for interpolation. I am not satisfied with the results, because the surfaces between contour lines are planes, not like a terrain slope. The surfaces do not like a real terrain visually because interpolation by moving average, weighted average and nearest neighbor do not consider factors, such as curvature, convex, and concave. Any help will be highly appreciated. Gaoming Fu LeRoy M. Dorman Scripps Institution of Oceanography, 0220 University of California, San Diego La Jolla, CA 92093-0220 voice: +1 858 534-2406 fax: +1 858 534-0784 inet: [EMAIL PROTECTED] http://www.mpl.ucsd.edu/people/ldorman Physical address: 436 Ritter Hall 8635 Discovery Way La Jolla, CA 92037 =========================================================================== To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message "signoff JAVA3D-INTEREST". For general help, send email to [EMAIL PROTECTED] and include in the body of the message "help".
