Smooth fading of actors depending on the distance

how can achieve a smooth disappearance of the actors depending on the distance to the end of the cull distance?
in other words: it is necessary to have a gradual disappearance of actors from point A to B.

I tried to add to the material of PerInstanceFadeAmount but it added the smoothing only at the end of the cull distance.

In this example we used a Grass type