Make fog additive?

Is there a way in a shader to make unity's fog additive only?

 

You can disable fog and calculate it yourself via shader. This will give you ability to blend it as you see fit (add, multiply, lerp etc)

I had similar challenge time ago and these blog entries proved to be very useful

http://www.software7.com/blog/unity-custom-fog-shader-on-windows-phone-8/
http://jakobknudsen.com/?p=224

 

Thanks!