Built-in volume cloud

[catnuko]

Volumetric-clouds-plugin Demo

A ready-to-use volumetric clouds plugin integrated into SkyMaterial. While it’s performance-intensive, the sky is no longer that monotonous, right?:wink: Port from: https://www.shadertoy.com/view/4dSBDt Demo: https://playground.babylonjs.com/#MAONNT#13