How to blur a shadow

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:bust_in_silhouette: Asked By sygi

I have a shadow catcher, which works correctly with a directional light, but I would like the shadow coming out of it to not have sharp edges, but rather blurred ones.

I tried:

  1. to convert the spatial material to a shader one and to use textureLod there, like this:
vec4 albedo_tex = textureLod(texture_albedo,base_uv,5.0);
ALBEDO = albedo.rgb * albedo_tex.rgb;
ALPHA = albedo.a * albedo_tex.a;
  1. to play with various settings of Directional Shadow in the light
  2. changing the filter mode and shadow atlas sizes
  3. changing between GLES2 and 3,
  4. creating two separate directional light, with slightly different angles.

but none of the options made the shadow to be blurry, ie. to make pixels closer to the edge of the shadow to have a smaller alpha.

Is there a way to achieve it, eg. by applying a post-processing effect to the shadow catcher?