Followup on Graphics3D rendering problem

*To*: mathgroup at smc.vnet.net*Subject*: [mg35754] Followup on Graphics3D rendering problem*From*: AES <siegman at stanford.edu>*Date*: Mon, 29 Jul 2002 03:13:29 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

I've been warned by others in the past that there is some serious flaw in Mathematica's PostScript rendering of 3D graphics, and now I'm running into it in a big way. I'm making a series of, in essence, "3D bar charts" using Graphics3D and Show to display vertical towers (Line[]s) of varying heights rising vertically from different points in a base plane; and some of the towers just aren't there -- just don't draw -- randomly as far as I can tell. A given tower will be there in one plot of a sequence, missing in the next one (when its height has changed somewhat), reappear a few plots later, and so on -- typically only one such tower in a given sequence of plots. This is causing me trouble big time. Is there a workaround? Specific commands or options I should avoid? Two add'l notes: 1) As a work-around I replaced all the thick Line[]s in the graphics with long skinny Cuboid[]s, and did not observe any of those to be randomly missing in any case I've tried to date. 2) I also realized that certain other Line[]s in my graphic were long enough to extend outside the PlotRange I had set in the Show[] command. After I corrected this, the randomly missing Line[] problem seemed to go away even when using Line[]s. That was a programming error on my part, but I think nonetheless also still a bug in Mathematica's rendering code: * PlotRange is essentially a windowing or masking command -- it's supposed to let you generate graphic elements that extend outside the plot range, then just not display them, right? (At least it does in many other cases.) * The Line[]s that randomly disappeared were not the Line[]s that ran outside the plotting range, and had no direct connection to them -- and they only disappeared in certain plots, while the overlength Line[]s were present in all the plots.