Could always just fudge it with an alpha'd shadow map that moves along the terrain at the same speed of the clouds above, it's how Zelda:Twilight Princess does it. ;/
You gotta say though, it really does bring things to life, otherwise the only thing that affects the lighting outside is static shadows from the placed-geometry, and the day-night/cycle if there's even one.
You gotta say though, it really does bring things to life, otherwise the only thing that affects the lighting outside is static shadows from the placed-geometry, and the day-night/cycle if there's even one.