SoftShadow shows incorrect shadow when objects merge

see in the attached patch how the shadow doesn t look real when the 2 objects merge together… is this a limit of the shader?

boxes.rar (25.0 kB)

You can tweak it to be better, some notes in the patch…
Basically set the depth of the depth map closer to the depth of the scene, to make best use of the depth buffer. (6.3 kB)