Ok, I want to render clouds... The clouds need to look good from a distance and still allow me to see sprites and stuff inside them, but also look like I'm *IN* a cloud while inside them looking out. Almost like a block of Fog or something... *shrug* What is your opinion of the best approach?

You can do volume-based fog using shaders.

Render begin and end range of fog as two pieces of geometry; subtract the "near" from the "far" to see how much fog you're in. This is similar to stencil shadows in a way.

DonnieDarko: while nice, I believe it would be overkill for the particular situation.

hplus0603: All of the Volume-Based fog that I've seen has been using OpenGL which I am unfamiliar with. Do you have a link to an example of a DirectX9 example? Ideally, I want to fill an invisible box with 'fog' in this situation. But I don't want to be limited to a box... I want to able to mold it into a large bulb if you will.

EDIT: Oh and one more thing. The clouds do not need to change shape. They are, in fact, static... afterall, they are clouds of dust stuck in a vacuum. :)

-E

There's a PDF out on the net from a developer that helped develop the clouds for MS Flight Sim which looks pretty good. I couldn't find it quickly but I'll try and find it this weekend (I have the PDF saved) if you cannot locate it and want it, send me a PM.