How to simulate cloud shadows on the ground (no actual clouds needed)

[Evgeni_Popov]

Self shadowing is a problem with exponential shadow map. See:

Blur exponential Shadowmaps generating a self-shadow that can't be fixed with bias

Exponential shadow map might get really tricky to get self shadow, I would recommend to use percentage CloserFiltering: https://www.babylonjs-playground.com/#JPVT2W#2 or PCSS in this case. In case you really want to use ESM, you can try the close ESM instead : https://www.babylonjs-playground.com/#JPVT2W#3

What you can try is to use close exponential instead, and set the shadow min/max values to appropriate values:

Babylon.js Playground