Fog Explained

[Rich Rosemann]

Hello All

Can someone explain the results of the switches in the Fog pop-up window?

Scattering:

Direction:

Absorbion:

 

Also, How does the Sun Intensity, Sun Highlight & Sky Intensity effect the switches, if at all.  I'm attempting to create a inclosed room with one or two windows with a transparent stained glass image decaled to them.  The glass is marked as thin.  (Much like Peters beautiful image, earliar).  I was able to get a nice fog effect on the onset, but with a few changes to the fog switches and the sun, I lost all fog effects.  The farther I adjusted, the worse it became.  Now I'm hopelessly lost.

 

Another question.  When sizing the Fog box, should it be sized inside the room, which is what I did, or does it matter?  Thanks

 

RIch Rosemann

 

 

 

[Roy Hirshkowitz]

Here's the original article I wrote in the wiki-- it might help.

 

The fog box shouldn't matter that much unless you're using clipping planes-- then you have to be careful not to clip out the front face of the box.

 

[Rich Rosemann]

Hi Roy

 

Thanks for the quick reply.  I forgot that you wrote this wiki weeks or months ago.  I probably have it in my archives, somewhere.  Of course, I did chop the box in two with a clipping plane.  Does the studio lights on/off effect the image.  Thanks again

 

Rich Rosemann

 

[Roy Hirshkowitz]

Not really-- studio brightness turns the sun and sky intensity down by 20X-- that's all.

[Albert D Hart]

I think you have to be careful that the fog box does not intersect (e.g coplanar faces) any other geometry such as the walls of the room. Otherwise the fog disappears.

[Roy Hirshkowitz]

Good point.  Don't bury the fog box inside a wall.

[Albert D Hart]

Rich also mentions a clipping plane.

Isn't there a problem with some combination of clipping plane, bounding box and camera?

[Roy Hirshkowitz]

Sort of covered above-- don't clip out the front plane of the box unless the camera is inside.