On 2007-07-21 21:08-0700 Jerry wrote: > When surface plots are rendered in Postscript on OS X, artifacts > appear if antialiasing is enabled. Each triangle used to compose the > surface has its edges antialiased against whatever color is behind it > causing in effect a narrow line to appear at the intersection of > every pair of edges. The overall effect is that the mesh of lines > connecting the points of the triangles is superimposed on the > surface, but with varying visibility depending on (the color of) what > what lies behind each edge. In some cases there appears a faux > translucence, partially revealing either the normally hidden part of > the surface or grid lines. In other words, I think that each triangle > is being antialiased as an individual entity rather than the entire > surface plot as a single entity.
Yes, this is a known problem, and I think your analysis agrees with what one other guy said who looked into the problem. The ideal solution of course is to not apply antialising to any surface, but his feeling was we were the victim of bad PostScript engineering that made that impossible for viewers to do. One crude but effective way to beat the problem is to apply all surfaces twice and slightly offset from each other. He sent in such a patch, but I never applied it because I was concerned that the postscript images would double in size and postscript rendering times would double. In case the analysis is correct AND Adobe have learned from this mistake, it is possible pdf's do not have this fundamental problem. Therefore, you might want to have a close look at results from Werner's pdf device or Hazen's pdfcairo device to see if this problem occurs for those cases. Alan __________________________ Alan W. Irwin Astronomical research affiliation with Department of Physics and Astronomy, University of Victoria (astrowww.phys.uvic.ca). Programming affiliations with the FreeEOS equation-of-state implementation for stellar interiors (freeeos.sf.net); PLplot scientific plotting software package (plplot.org); the libLASi project (unifont.org/lasi); the Loads of Linux Links project (loll.sf.net); and the Linux Brochure Project (lbproject.sf.net). __________________________ Linux-powered Science __________________________ ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
