On Thu, Aug 28, 2008 at 8:01 AM, Arnaud Bergeron <[EMAIL PROTECTED]> wrote: > > 2008/8/28 William Stein <[EMAIL PROTECTED]>: >> >> On Thu, Aug 28, 2008 at 5:06 AM, mhampton <[EMAIL PROTECTED]> wrote: >>> >>> There are a number of things I am sort of working on but I lack the >>> time to do them in the near future. >>> >>> 1) Better triangulations for many-vertex faces. You either have to >>> work around the current behavior of indexed_face_set or change it. I >>> have been trying to do the former in polyhedra.py, since then it only >>> impacts things in that module, but my current efforts are kind of >>> sad. That's why .render_solid() is commented out in groebner_fan >>> right now. My current effort tries to get a triangulation from random >>> lifting but I must be doing something stupid since it fails sometimes >>> on pretty small faces. > > I will do that. > >> Could you explain what "random lifting" is? >> >>> 1b) A 3D polygon command. This could easily be built off of the >>> polyhedra code if the triangulation there was fixed. >> >> Could you clarify what is broken? I didn't know that triangulation is >> broken. > > Triangulation for many-vertex faces is, it seems. Or at least that's > what mhampton says. > >>> >>> 2) Animations. I'm not sure how to really fix this. For small, >>> simple animations its OK to use convert and get an animated gif, but >>> that starts getting awkward quickly. I have been playing with using >>> Blender to get nice movies of animations (e.g. compressed jpeg avi). >>> It would be very cool to have a Blender spkg, although it would be >>> huge. But having an experimental one would be a big step forward; >>> maybe we could figure out how to carve off the pieces we needed. >> >> I definitely don't want to maintain such an spkg, especially since if >> blender is any good as a project (and it is!) then one should be >> able to easily install it on ones computer independent of Sage. >> Making an spkg should only be needed if we need to binary link >> Sage to a program, hence build it with special options, or the program >> has a relatively small user base and is hard to install (e.g., polymake, >> etc.). For this application, can't one just write some data to a >> file and run blender as a subprocess. > > For 3D animations, this is a great idea. I'll look into it, but maybe > mark it as optional for my project, which means I'll do it if I have > the time. > >> Another way to make animation for a web browser would be >> to use javascript, though the timing might look jerky. Another >> possibility is flash. > > That would be for 2D animations right?
Yes, that's what I had in mind. It could also be used for 3d if you generate a sequence of 3d png plots using tachyon3d, which is possible (though currently very awkward). >>> 3) Color functions for 3D plots. I should have put this first since I >>> miss it in both teaching and research and it probably isn't too hard >>> to do. Basic examples of what mathematica can do in this regard are >>> towards the end of: >>> http://reference.wolfram.com/mathematica/tutorial/DensityAndContourPlots.html >>> ...not that its a paragon of user friendliness, but just to clarify >>> what I mean. > > This is like a continuous contour plot, indicated by colors, right? > If so, I'll do that too. Yes. It could also be used for visualizing a complex-valued function of a complex variable. Over the point (x,y) in the plane (which corresponds to x+I*y), draw a point abs(f(x+I*y)) whose color is given by arg(f(x+I*y)) in [-pi, pi) (or some normalization of arg). The color could use the hsv function. > >> The plot3d(..., adaptive=True) puts colors in the plots, so looking >> at the code might provide a useful hint. >> >>> >>> 4) Getting image maps working better with tachyon. Last I knew these >>> were sort of broken and used a somewhat unusual file format (ppm?). >>> It would be nice to have those working better. > > Do you mean texture for object? If yes, I can do that too. It might > need some hacking in tachyon itself, but I'm not against that. Yes, that's what I think he had in mind. > >> That's a great suggestion. Can jmol also do image texture maps? >> >>> >>> Hmmm...I know I have others but those are what I think of first. > > >>> Cheers, >>> Marshall Hampton >>> >>> On Aug 27, 10:49 pm, "Arnaud Bergeron" <[EMAIL PROTECTED]> wrote: >>>> There is a strong possibility that for the next semester I will be >>>> working on the graphics area of sage. I would working more on the >>>> visible side than the innards but that does not mean I will not touch >>>> the innards if need be. >>>> >>>> Currently I have these items that I think need work / I would like to work >>>> on >>>> >>>> - better implicit plot >>>> - volumetric rendering (like a contour plot, but in 3D) >>>> >>>> If you have any area involving graphics (that includes animations) or >>>> visualisation that you would like someone to work on, feel free to >>>> chime up. I need more items to work on anyway. >>>> >>>> Arnaud >>> > >>> >> >> >> >> -- >> William Stein >> Associate Professor of Mathematics >> University of Washington >> http://wstein.org >> >> > >> > > > > -- > La brigade SnW veut vous recruter - http://brigade.snw.googlepages.com > > > > -- William Stein Associate Professor of Mathematics University of Washington http://wstein.org --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
