This addition is something I suggested in October: fog. Not only fog, but any partially opaque medium. Hence I called it MediumAttributes. You could simulate blue sky or green dirty water, well... I expect you to be creative. For the purpose of this demo, however, let's get back to fog. MediumAttributes gives you basic control on its location; for example, you could make it to look like this:
This is different from cube demo in that this time I have specified optional parameters, fadeFrom and fadeTo vectors:
var medium:MediumAttributes = new MediumAttributes (0xFFFFFFFF,
new Vector (0, -10, 0), new Vector (0, -100, 15), 200);
Hopefully, someone will make nice tutorial for this. For now, I can offer this image to help you understand the way it works:
