smaller 

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/plot3d@72 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
even smaller, resolution = 100

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/plot3d@73 edb9625f-4e0d-4859-8d74-9fd3b1da38cb