Thank you for your excellent work on canvas3d! I never imagined
canvas3d finding a place on smartphones, but this is really exciting.
Maybe someday Sage could be an iPhone app!
We should figure out how to incorporate this code into Sage. Is is
legal for us to use a modified version of Pre3d? Peter, in your
opinion what kind of work remains to be done on this code for it to be
ready? You mentioned two issues:
- Mouse movement is erratic (I noticed that rotation would continue
to follow my mouse even after I released the button). I see that
you're using Pre3d's autoCamera(), which seems to work in the demos on
the Pre3d website. What's going wrong here?
- Lines aren't depth sorted. I don't know that much about computer
graphics, so I don't know how hard this problem would be to solve.
We might also want to create a Trac ticket to incorporate your other
improvements to canvas3d -- namely, a json_repr() for line objects and
support for touch gestures on the iPhone -- separately.
I would be happy to help with this.
On Oct 3, 4:04 pm, Peter <peter.jip...@gmail.com
> Thanks to the pointer to Pre3d it is now possible to do shaded
> performance is not quite like jmol, but it is far better than I would
> have expected (especially with Chrome), and it has the advantage of
> working on the iPhone (and perhaps Android -- can someone with an
> Android phone please check?). The surfaces display in IE, but mouse-
> tracking is erratic at the moment. Texture mapping is also possible,
> but not yet exposed to Sage.
> for a standalone html version,
(lots of) surfaces
> produced by Sage
> (try putting that many jmol applets on one html page :-)
> I have modified the Pre3d .js files to be a drop-in replacement of
> canvas3d_lib.js. Basically this meant combining them into a single
> file called canvas3d_lib.js, adding code to parse Sage json files,
> extending Sage and Pre3d to handle lines, opacity, and tweaking Pre3d
> to shade both sides of the surface etc.
> In order to be efficient, Pre3d takes some shortcuts that imply
> certain limitations. E.g. intersecting faces do not get split
> automatically into subfaces, so intersections of surfaces are jagged.
> Also lines are drawn on top of surfaces (so no hidden line removal).
> There are two patches that need to be applied to Sage-4.1.2.rc0 to
> make this viewer="canvas3d" option work: