Custom shading - Grainy

is there a possibility of getting an non photorealistic shading similar to the one attached.
a way to purposely have the shadows grainy?

I am working on a shader that does exactly this. It will be part of a shader pack I hope to have on the market place before the end of May.

One cheap way to do it is to generate a black and white noise texture, do a simple Phong lighting calculation in and unlit shader, and blend the results with your stipple (noise) texture. The basic Phong calculation is NdotL. Take the surface normal and dot product with your normalized light vector. The version I am working on is a bit more complicated, but the explanation I gave gets you a chunk of the way to a good result.

excellent. the method you describe is not entirely clear but it gives me a good starting point. thank you.
also you have yourself a customer. will your shader pack be more of the NPR?
cheers.