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View Full Version : Is there a setting for fog to affect rendrd alpha?



Ty Towriss
06-16-2003, 10:19 AM
Is there a setting for fog to affect rendrd alpha?

Mylenium
06-16-2003, 12:35 PM
No, LW's normal Z-Buffer fog does not affect alpha (it would not make sense anyway).

Mylenium

Ty Towriss
06-17-2003, 05:32 PM
Well I have a situation here, and have run across many times, where it does make sense. And even the phone support rep said that they have reqested the developers to include this as an option for fog to affect alpha.

Mylenium
06-18-2003, 12:12 AM
Well, I meant no sense in a mathematical way. You see, Z-Buffer fog will always have a certain maximum value at a given distance - if that was added to the alpha, the alpha would be more or less useless (for 100 % it would be totally white). Even for everyday tasks this may not be practical. I very much prefer saving the depth buffer or even create a separat pass for the fog. Basically all you need to do is create black object without any further shading and set your fog to white as color. The resulting b/w image can easily be used in compositing.

Mylenium

Ty Towriss
06-18-2003, 08:15 AM
Thanks for the workaround info. This is exactly what I was in the process of doing when I posted the question. It was a lot of extra work for just a simple check box... fox affects alpha of the objects affected by fog. But thanks for your response.