Just use this funcion MakeFog() wenever you want to use fog.


function MakeFog()
{
camera.fog_start = 8000; //Distance
camera.fog_end = 10000; //Max range of the fog
fog_color = 1;
d3d_fogcolor1.red = 64; //Choose the colors
d3d_fogcolor1.green = 64; //Choose the colors
d3d_fogcolor1.blue = 64; //Choose the colors
}