in threejs i was able to change the depthmaterial on each mesh to discard the same way the dissolve runs and i would get the shadow to reflect what was going on the mesh.
https://www.babylonjs-playground.com/#I669IL
how can i get the shadows to dissolve in babylon since it doesn’t have the depthmaterial that threejs has?
what does the depth material do?
You need to provide your own shadow material to the shadow generator to account for the specificities of your custom material:
https://www.babylonjs-playground.com/#I669IL#6
I have simply copied the standard shadow map vertex and fragment shaders used by the shadow generator and added the check to discard the fragment based on the noise value.
It’s a bit complicated, maybe we should think of a better way to handle this…
Note that I have disabled back face culling on the sphere, as it’s probably what you want for the shadow to be correct.
You can get some more info here: Mesh with custom shader material does not cast shadow
yes thats what i am going for. 
but it looks like its doing it on the entire scene instead of each observable.
i added a box
https://www.babylonjs-playground.com/#I669IL#4
i updated the effect values per object and now its doing what i expect. it was holding onto the effect values per observable.
https://www.babylonjs-playground.com/#I669IL#5
and yeah, id agree this is a very weird way of doing it.
@Evgeni_Popov now the problem i see is if i want different shader effects for different shadows.
would i just have this giant shadow shader that i need to reset values on every observable. it doesnt look like i can quite make this dynamic per shadow very easily, i tried updating the shadowGenerator.customShaderOptions after each observable but it didnt do anything.
Yes it’s the problem, as I said I think we need to think about this and see if we can come up with a better solution…
As an aside, how would you have used the depth material in threejs to achieve this effect? I looked at the doc of this class and could not see how it could make it worked.
[…] Ok, it is not through the MeshDepthMaterial class (what I was looking at) but by setting the customDepthMaterial / customDistanceMaterial properties it seems.
yeah sorry, its the customDepthMaterial that i was using.
thanks for your help again! and thanks for looking into it!
We are checking with @Evgeni_Popov how we could make this one happen as I love the idea of being also able to use it with Node Material 
Agree!
That’s a lot easier now with the new ShadowDepthWrapper (documentation coming soon):
I love what you did!
Sorry for the late response! We are about ready to deploy our project so i was finally able to test this out.
I love the new implementation, its so much easier!
But…
I am seeing significantly slower speeds when initializing objects using it compared to the work around.
I am also seeing the shadow generated flicker when resizing the screen and running engine.resize()
I will see if i can get tests in a playground to validate these issues when i get a chance…
again thank you! cannot wait to start using 4.2!