Hi pfGurus, Sorry again. A last try, and after I will give up, crying alone in front of my screen. I have a problem with LPointState attributes of pfGeoState. I have loaded the "3010.star" file from the Performer data directory. I want to control the intensity of the Stars, to be able to make them gradually disappear from my channel. I have got the pfGeoState of the only geoset of this geode, and I have attributed a LPointState attr to this pfGeoState. As shown in the attached file testStars.C, I have set a null intensity to the LPointState. Unfortunately, my stars are as much visible as before. What's the problem ? Is there a bug ? Does someone know some special features for the .star files ?? Background : I am making a spacecraft simulation, where I simulate the atmospheric effect, making the sky blue (changing the pfEarthSky) and the stars unvisible when I am landing on the earth. But my stars are always visible. In the attached sample code, I have directly set a null intensity for the stars state, but even in this case there is no effect. I am compiling with IRIS GL, on an 2 CPU 1 RM ONYX with IRIX 5.3. waiting for answers, Mike