Enviromental Fog invisible area

[AndyGandy]

Hello!

Is there any way to make a fog in the scene with gradient mapper or using some kind of clip planes with fadeouts? What I need:

Scene is:
Camera ----> Objects1 ----> Objects2 ----> Background
0__________100__________200_________300 units
Fog is:
NO FOG ----> NO FOG ----> FOG STARTS ----> FULL FOG (Invisible background)

I wish to make fog transparent absolutely in radius of 200 units from the camera. Then from 200 to 300 units fog start to appear gradiently and in 300 units fog makes absolutely untransparent.

Using of map on "Fog density" channel is dramatically drops the render time so this option is useless for me.

Any other ideas?
What is the fog fadeout? I cant understand it even after reading the manual. Fadeout from what point? From fog distance point?

Thanks!

[AndyGandy]

And a second question. Is env fog supported by RT?

[AndyGandy]

A little scheme of my requirements. Is it real to do?

[vlado]

The fadeout is from the boundaries of any gizmos attached to the fog.

I'm afraid mapping the fog density is the only way to do this. You can adjust the step size through the fog to control render times.

It is not supported in V-Ray RT currently.

Best regards,
Vlado

[AndyGandy]

Rgr that. Thanks!