Naomi, I seem to remeber reading an article in the C/C++ Users Journal (CUJ) about three years ago about rendering 3D contour plots using OpenGL. The trick was to use a 1-dimensional, 1-bit texture map oriented perpendicular to the map plane. The texture consisted of zero bits between the contours for transparent sections and 1-bits to render the contours themselves. The techinque stuck me as an elegant and high-performance solution to rendering contours without needing any compuational geometry. I have no idea if it is possible to implement this using Java3D - somebody more experienced with Java3D texturing and transparency should be able to help...
Rob Smallshire www.smallshire.org.uk -----Original Message----- From: Discussion list for Java 3D API [mailto:[EMAIL PROTECTED] On Behalf Of sikander hayat Sent: 28 January 2004 09:48 To: [EMAIL PROTECTED] Subject: Re: [JAVA3D] contour plots how to make a NURB surface in java 3d using directx... Are there any algos available online ? On Wed, 28 Jan 2004 GOBE HOBONA wrote : >Naomi, > >An approach to creating planes with contour maps is: >1. Triangulate the spot heights using perhaps the Delaunay Triangulation >method >2. Interpolate the heights from the triangles to determine isolines >3. Render the 2D birds-eye view onto a BufferedImage >4. Pass the BufferedImage to an ImageComponent2D to drape it over a >GeometryArray created with triangles from step 1 > >About step 1 >If you are handling a regular grid then you do not need to implement the >Delaunay Triangulation method as Java3D's Triangulator Class can handle >this, however if you are handling irregularly positioned points then you >need to first cluster the points into triangles to create a Triangular >Irregular Network (TIN), pass all points to a GeometryInfo object with a: >stripcount array of length = number of triangles found from Delaunay >each element in the array = number of points in a triangle (3) > >If there isn't an easier way, I hope this approach helps you. It worked for >me :-) > >Cheers, >Gobe Hobona >PhD Student in Geomatics >University of Newcastle upon Tyne > >> From: Naomi Greenberg <[EMAIL PROTECTED]> >>Reply-To: Discussion list for Java 3D API <[EMAIL PROTECTED]> >>To: [EMAIL PROTECTED] >>Subject: [JAVA3D] contour plots >>Date: Tue, 27 Jan 2004 12:32:02 -0500 >> >>I am looking for some guidance. I need to produce a plane above, below or >>through a 3D body with a contour map of the surface at that cut. Does >>Java3D support contour maps? How do I do it? Are there any code samples, >>books, etc that a novice like I should look at? >> >>Thanks, >>Naomi Greenberg >> >>====================================================================== ===== >>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". > >_________________________________________________________________ >Find a cheaper internet access deal - choose one to suit you. >http://www.msn.co.uk/internetaccess > >======================================================================= ==== >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". Sikander Hayat F/0 Engineering and Technology Jamia Millia Islamia New Delhi ----------------------------------- + LIVE BY THE SWORD,DIE BY THE SWORD | ----------------------------------- + ======================================================================== === 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". =========================================================================== 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".
