C4D: Applying spot shader only on shadows


#1

I use Cinema4D Studio R17, and have been trying to mimic the screening procedure used by manga artists.
I want to overlay uniform spots on top of the shadow regions only, and no other place even if light does not illuminate it.

A comparable result is shown in the image below (I’m referring to the shadows only):
http://adriftonvulcan.com/wp-content/uploads/2015/06/harrys-shadow.png

So far, I have been able to spot shade both the shadow and unlit regions, but not the shadow regions alone.

I have made several attempts to achieve this using an infinite light with ray-traced hard shadows, and tried to tune the Diffuse and Shadow parameters in the Spot shader but to no avail.

Appreciate any help regarding this.

Best,
pYro