> Can you post a sample ?
Basically, this is what I'm doing. The light won't affect the plane, but it
will highlight the ball.
light_source {<1,1,-1>*10 1 groups "walla"}
plane {y,0 pigment {rgb 1} light_group "!walla"}
sphere {y,1 pigment {red 1} finish {phong 1}}
