On Sep 23, 2007, at 3:37 PM, Alan W. Irwin wrote: > Actually, it is not simply spacing. If you look at the first attached > screenshot for the latest x28c.c, the disparity of length of string > for the > z=zmin case for omega = -Pi/4 (the string only goes ~ 40% to the > corner) and > omega = Pi/4 (the string goes well beyond the corner) is increased > for this > more extreme viewing angle but basically confirms the previous > results. > However, please also look at the shape of the "o" characters in > those two > strings. They are almost perfectly round (as directly viewed) > which means > their inferred 3D shape is strongly elliptical. Of course, the > inferred 3D > shape should be circular. To solve this issue the -Pi/4 (short) > string > needs all its characters stretched out along the axis of the string > while > the Pi/4 (long) string needs all its characters compressed along > the axis of > the string. The size of those characters perpendicular to the > string axis > look pretty good in both cases. Note, the screenshot also has similar > rotation results for x=xmax, and y = ymax. The errors are much > more subtle > for those cases, but they are there as well. Also, you can make > the errors > for those cases arbitrarily large by picking extreme viewing angles > (such as > azimuth = 85 or so).
Ok, but the ability to arbitrarily transform characters is not supported by some of the drivers, like aqt. In theory the cairo drivers could support this, but as currently written they also do not. When I was writing plptex3 I was thinking more faux 3D rather than true 3D character rendering, but it does seem reasonable that we should strive for the true 3D case. I believe that this will be a bit complicated however so I propose waiting until the after the next release. -Hazen ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
