Added event handler to shader code so that alphaCuttOff, transparency and sampleDensity are controlled via 'a', 't' and 'd' respectively.
Added event handler to shader code so that alphaCuttOff, transparency and
sampleDensity are controlled via 'a', 't' and 'd' respectively.


git-svn-id: 23b6355f2bb369032457de4eb5f713ee134f73a8@4502 16af8721-9629-0410-8352-f15c8da7e697

joevandyk/osg,joevandyk/osg,joevandyk/osg,joevandyk/osg,joevandyk/osg