vrayAerialPerspective not working at times

[stevesideas]

I have a scene from max 2014 where I'm using the above environment effect. It works sometimes and not others. All I did was change the HDRI in the dome light and the effect stopped working. I tried adjusting the parameters and nothing happens. This happened for the other HDRI but suddenly it started working so I'm not sure what is going on.

[matanov]

Do you have VRaySun in the scene ? The Aerial Perspective needs a VRaySun to work.

[stevesideas]

That works thanks. It seems I can turn the sun off and it will still work.

[matanov]

Yes, it needs only the position of the sun for the calculations.