surfo

workaround for surface lighting with OpenGL

There's a bug in the OpenGL renderer that produces faulty face lighting in surface plots, see picture above and http://www.mathworks.com/matlabcentral/newsreader/view_thread/249184 .
This submission contains a function that computes face normal data for the 'VertexNormals' property of the surface that fixes the lighting (facenorm.m) as well as a workaround function that you can just use in place of surf (surfo.m).

Only use this if you get erroneous surface plots and you can't go without OpenGL and flat lighting.