simulate cloud material shader on a mesh

panic

Hi,
Is there a way to simulate the rim lighting effect, blending of the rim light, and the opacity of the edges on a mesh to make it look like a cloud.
This would have to be in the material shader to apply to a mesh. no particles.
the edges would be a alpha map or some channel in a diffuse or normal map

Is there a tutorial of some kind i can be pointed to.

Thanks