you could try the tension-map addon…I personally haven’t mess with it, but theoretically it should work (making a vertex-colour layer to drive the opacity, with the attribute node).
After a “few weeks” experimenting (from time to time)…
The “tension-map addon” seemed to have been discontinued. (I can’t find it)
But I’ve worked out a possibility.
After all I’m not good in geometrical maths and so it’s running aceptable but not perfect.
A little Script in OSL like a “Mix Shader”: