yes 3dgs supports shaders but the problem begins when i want drop shadows on other block also with shader effect

about lights 3dgs only supports stencil shadows z-buffered
volumetric shadows are based on distance between light source and objects these kind of shadows produces that the shadows looks bigger when the object is near to the light source or smaller when the object is far to the light source

z-buffered shadows only produces far shadows or near shadows but the scale is the same.

any suggestion?

i believe that volumetric shadows can be coded but you need good shader knowledge