The original thread was about rendering an ellipsoid using plot: http://jsoftware.com/pipermail/programming/2015-March/041251.html
I couldn't figure out how to get plot to render one, so I came up with this: https://www.shadertoy.com/view/XtlGDX Skip managed to work out some J plot examples: http://bit.ly/1Be186L http://jsoftware.com/pipermail/programming/2015-March/041280.html And then the thread got off on the issue of texture mapping and the fact that someone needs to bring the opengl labs forward (since the J6 labs are based on an archaic implementation of OpenGL and the laziness inherent in human industry suggests that we should get things working now, while we can, before more things break). Anyways, it's good to hear from you. Thanks, -- Raul On Thu, Mar 19, 2015 at 8:17 AM, Cliff Reiter <[email protected]> wrote: > I forget the original thread. Are you trying to plot ellipsoids (egg > shapes)? > You can modify the scale factor in spherical coordinates for each axes: > x = rx (sin t) cos f > y= ry (sin t) sin f > z = rz cos t > where 0<: t<2p1, 0<:f<:1p1 and rx, ry, rz give the axis lengths parallel to > x y and z axes. > Do you need to rotate this in space? > > On 3/19/2015 1:44 AM, Raul Miller wrote: >> >> >> https://johncarlosbaez.wordpress.com/2015/03/17/planets_in_the_4th_dimension/ >> looks like a plausible approach for finding parametric descriptions of >> ellipses. >> >> I've not tried it, though. >> >> Thanks, >> > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
