Incorrect direction of shadow after enabled Exponential shadow map

[kzhsw]

Version: 8.3.1
Engine: WebGL2
Playground:

Babylon.js Playground

Steps to reproduce:

1. Open the playground
2. Look at the shadow

Expected:
It looks something like if “Exponential shadow map” not enabled.

Actual:
Shadow appears at both direction.

Notes:
Blur exponential shadow map suffers the same issue here

[Deltakosh]

cc @Evgeni_Popov

[Evgeni_Popov]

It’s a known problem with ESM where shadows are generated for geometry that is below the shadow receiver.

You can fix it in different ways:

• make sure the pipe doesn’t go below the plane: https://playground.babylonjs.com/#IIZ9UU#501
• set a nearer shadow far plane and tweak the depth scale to make it look good: https://playground.babylonjs.com/#IIZ9UU#502
• use CESM (you should also set a light.shadowMaxZ value so that the shadow is not too faint): https://playground.babylonjs.com/#IIZ9UU#503