A re-implementation of mesh cloud described in Sea of Thieves: Tech Art and Shader Development
Basically, it pre-compute occlusion lobe on mesh vertex and use it for real time shading.
A comparasion of ground truth and approximated shading:
Left: Houdini's cloudlight node, LeftMiddle: Per vertex raymarching ground truth. Middle: Approximation using occlusion lobe. RightMiddle: Lambert. Right: Combine occlusion lobe and lambert.
After vertex shading, multiple pass of post-processing is employed to blur and distort the buffer, finally composite into background.
Here I didn't sculpt the cloud mesh by hand, instead I generate clouds with L-system in Houdini
Some animations(GIFs, please wait for loading)
My blog On Mesh Cloud Rendering – Reimplement Sea Of Thieves’ Cloud
Unity 2018.4