float scaled_shadow = max( shadow, 1.0 - max(g_sun_dir.y,0.0) );
vec3 ambient = mix( g_ambient_colour.rgb, g_sunset_ambient.rgb,
float scaled_shadow = max( shadow, 1.0 - max(g_sun_dir.y,0.0) );
vec3 ambient = mix( g_ambient_colour.rgb, g_sunset_ambient.rgb,