On Wed, 5 Nov 1997, Stephen Chenney wrote: > Subject: Re: splines ??? > > > Hi, > > we plan to model a roller coaster in VRML. > > > > 1. Does anybody know if there are splines in VRML? > > > > 2. If not, does anybody have an idea how to model the rail? > > We're planning a similar thing (actually, the same thing). > > I see three options: > - Use an off-line process to generate a mesh. > - Use an extrusion > - Use a java program to create the geometry on the fly > (reduces download, but prevents some optimization by the browser). > FYI, I have implemented Non-Uniform Rational B-Splines PROTOtypes using Java in the Script node. This is available from http://www.ocnus.com/NURBS/ Source code is included, so you can modify it to fit your needs if necessary. Send me suggestions for added functionality. This does reduce download time, since the mesh is generated programatically. The way I have implemented it *does* allow the browser to perform optimizations (I believe) since the resultant mesh is just another IndexedLineSet/IndexedFaceSet. And of course you should be able to modify the shape of the spline and degree of tessellation at run-time, although in practice this is prohibitively expensive in terms of CPU to do very often. Tim. ------------------------------------------------------------------- *** Please send administrative requests to <majordomo@sdsc.edu> *** -------------------------------------------------------------------