transparent surface in rgl
On Wed, 5 Oct 2005, Duncan Murdoch wrote:
On 10/5/2005 9:31 AM, Prof. Paul R. Fisher wrote:
Hi all I am a complete newbie to this list (just subscribed) and a newcomer to R (an S user from olden times). I have been using scatter3d to create a 3d scatter plot with surface. The graphic is created within the rgl package and I have used rgl.postscript to export it so I can generate a publication quality image. My problem is that the plotted surface is no longer transparent in the postscript output ie. the rgl.spheres that are behind the surface disappear in the postscript image. Can't seem to find any info on this anywhere. Am I doing something wrong? Is there an easy fix?
I think Postscript doesn't support transparency (or at least the version of Postscript that the rgl.postcript function targets doesn't support it). You may have to export a bitmapped format using the rgl.snapshot() function. If your original window is very large this may give you good enough quality.
Common PostScript (level 2) does not support either full or partial transparency (and I guess partial transparency is meant here or the surface could just not be plotted). It would be good to have a rgl.pdf which did. These days PDF is the `portable PostScript' and since version 1.4 has had alpha-channel supoort. Ref: http://en.wikipedia.org/wiki/Transparent_pixels#Transparency_in_PostScript
Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595