Doing that will not look very good.
For one, unless your terrain is perfectly flat, the shadow mesh will intersect the ground... half of it will be cut off.
For another, if you use a blending mode overlapping polygons will create areas that are darker than others. It'll look like a bunch of triangles of different shades.
For one, unless your terrain is perfectly flat, the shadow mesh will intersect the ground... half of it will be cut off.
For another, if you use a blending mode overlapping polygons will create areas that are darker than others. It'll look like a bunch of triangles of different shades.