The High Definition Render Pipeline (HDRP) provides a type of fog called Linear Fog). Linear Fog enables you to linearly increase the density of fog at a certain distance from the Camera. The fog density increases until it reaches a maximum density at a further distance.
Using Linear Fog
To add Linear Fog to a Volume, select the Volume component in the Scene or Hierarchy to view it in the Inspector, then navigate to Add override > Fog and click on Linear Fog.
After you add a Linear Fog override, you must set the Volume to use Linear Fog. The Visual Environment override controls which type of fog the Volume uses. In the Visual Environment override, navigate to the Fog section and set the Type to Linear Fog. HDRP now applies Linear Fog to any Camera this Volume affects.
|Density||Use the slider to set the maximum density of the fog. This acts as a global multiplier. Higher values produce thicker fog.|
|Fog Start||The distance from the Camera at which the fog density begins to increase from 0.|
|Fog End||The distance from the Camera at which the fog density reaches the value you set in Density.|
|Fog Height Start||The height (in world space) at which the fog density begins to decrease.|
|Fog Height End||The height at which the fog density reaches 0.|
|Max Fog Distance||The maximum distance of the fog from the Camera.|
|Color Mode||Use the drop-down to select the mode HDRP uses to calculate the color of the fog. Sky Color: HDRP shades the fog with a color it samples from the sky cubemap and its mip maps. Constant Color: HDRP shades the fog with the color you set manually in the Constant Color field that appears when you select this option.|
|Mip Fog Near||The distance (in meters) from the Camera that HDRP stops sampling the lowest resolution mip map for the fog color. This property only appears when you set Color Mode to Sky Color.|
|Mip Fog Far||The distance (in meters) from the Camera that HDRP starts sampling the highest resolution mip map for the fog color. This property only appears when you set Color Mode to Sky Color.|
|Mip Fog Max Mip||Use the slider to set the maximum mip map that HDRP uses for the mip fog. This defines the mip map that HDRP samples for distances greater than Mip Fog Far. This property only appears when you set Color Mode to Sky Color.|
|Constant Color||Use the color picker to select the color of the fog. This property only appears when you set Color Mode to Constant Color.|