[ts][threejs] Custom shader ignores light and shadows

[davidetan]

As reported by a user in this forum thread, the custom shader we use to render our meshes does not take into consideration lights and shadows.

It seems that using the onBeforeCompile callback is possible to modify the threejs base shader rather than replacing it.

See this official example (code here).

Moreover, 0.158.0 adds support for BatchedMesh: https://github.com/mrdoob/three.js/releases/tag/r158