You're right - if I just change the surface to be opaque, some of the scatter points randomly disappear and reappear depending on "camera" angle.
So how does it decide which points are behind/in front of the surface, then? I can't figure out any obvious pattern... And is it possible to use the z-order mechanism to get around this? (e.g. individually set the z-order of scatter points and the patches in the surface so that at least very roughly the correct pieces are rendered in front?) On Mon, Oct 4, 2010 at 1:04 PM, Benjamin Root <ben.r...@ou.edu> wrote: > On Mon, Oct 4, 2010 at 2:21 PM, Erik Tollerud <erik.tolle...@gmail.com> > wrote: >> >> I've noticed some odd behavior in the mplot3d toolkit when using >> scatter3D with plot_surface. What I want to do is generate the >> surface with an alpha level of 0.5, such that any points that are >> between me and the surface should come out fully opaque, and any >> points behind the surface should be rendered blended with the surface. >> Instead, the scattered points are blended with the surface regardless >> of whether they are in front of it or behind. There's also a weird >> behavior where, depending on the viewing angle, the points will >> suddenly snap from fully opaque (even if behind the surface) to >> transparent. An example is attached, with renderings of the two >> states in the URLs below. >> >> Is this a bug, or am I doing something wrong? >> >> http://dl.dropbox.com/u/8683962/mpl3dalpha-1.png >> http://dl.dropbox.com/u/8683962/mpl3dalpha-2.png >> >> -- >> Erik Tollerud >> > > At first glance, I wonder if this is just because of mplot3d's naive > approach of figuring out what is behind other things. mplot3d doesn't do > any sort of physics or ray-tracing to figure out how elements are positioned > relative to the camera. Try it again with perfectly opaque surface and > dots, and I bet you will have dots "magically" appearing in front of the > surface at certain viewing angles and then disappearing. > > Note, I have only looked at the photos, not the code. > > Ben Root > > -- Erik Tollerud ------------------------------------------------------------------------------ Virtualization is moving to the mainstream and overtaking non-virtualized environment for deploying applications. Does it make network security easier or more difficult to achieve? Read this whitepaper to separate the two and get a better understanding. http://p.sf.net/sfu/hp-phase2-d2d _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
