For texture mapping, I think you'd need to abandon plot (at least as it is currently written) and move over to opengl.
For opengl, you either need to drop back to earlier versions of J (J6 and J7 both had opengl labs - albeit with differences in the details) or you'll need to explore the webgl capabilities inherent in JHS or you'll need to temporarily abandon J while you learn the ropes (perhaps at shadertoy) and then maybe bring your knowledge back into the community. References: http://www.jsoftware.com/jwiki/OpenGL http://webglplayground.net/documentation https://www.shadertoy.com/results?query=tag%3Dtexture Or, if you are less inclined towards experimentation and prefer some heavy reading: https://www.cse.msu.edu/~cse872/tutorial4.html https://www.opengl.org/archives/resources/faq/technical/texture.htm http://www.glprogramming.com/red/chapter09.html ... Beware though that the opengl standards have drifted over the years and there will be subtle gotchas where some older things no longer work and some newer things don't quite work exactly like they are described to work. What usually works for me is some time spent finding out what the puzzling terms mean, and then some blind experiments based on some working example - go back and forth on that enough and mix in some attempts to create things from scratch (which helps identify blind spots). But I also like to stay close to working examples, as much as I can, to avoid too much time lost on blind alleys (where someone with more self importance than practical sense says something which sounds plausible but which is totally unrelated to what you want to be doing). Thanks, -- Raul On Sat, Mar 7, 2015 at 3:10 PM, Skip Cave <s...@caveconsulting.com> wrote: > My next challenge is to map a texture (rectangular .jpg image) onto that > ellipse and plane. Any hints as to how to do that? > > Skip Cave > Cave Consulting LLC > > On Sat, Mar 7, 2015 at 1:35 PM, Skip Cave <s...@caveconsulting.com> wrote: > >> Raul, Thanks for the links! That's what I needed. I didn't think about >> looking in the Studio Labs for the Plot documentation. The final secret is >> to throw away the imaginary parts of the ellipse equation so all z outside >> the ellipse is zero: >> >> a =.1 >> >> b=. 1.7 >> >> c =. 1.5 >> >> x =. 5 %~21 21 $ i:10 >> >> y =. |: x >> >> z =. {. |: +. c * ((1 - ((x^2)%(a^2)) + ((y^2)%(b^2))))^0.5 >> >> 'surface' plot z >> >> >> Here's the plot: http://bit.ly/1GbYuy1 >> >> >> The axes should be 1, 1,7 and 1.5, but they are not, so I need to look at >> that. >> >> >> Skip >> > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
