volumetric spotlight optimizations


git-svn-id: svn://svn.tuxfamily.org/svnroot/tesseract/main@1736 b412e182-2ed4-4078-95c4-27dc59f57fa9
more volumetric spotlight optimizations


git-svn-id: svn://svn.tuxfamily.org/svnroot/tesseract/main@1737 b412e182-2ed4-4078-95c4-27dc59f57fa9