Hi Dr. Sassi,
I want to share what I have done with the vertex map technique and resolve one problem with this solution.
https://youtu.be/-w2yPYcm8SY
What I have now is for my sufficient. I think I don't need complex self-shadowing because as you can see in the example there is a solid black toon shadow,
that covers this area of the model.
But there is one problem.
There are two options connecting to Plight

1. if from node "Point" I connect Point normal to Normal in Plight - Light rotation is working, moving object is working, rotating object is not working;
2. if from node "Point" I connect Point position to Normal - Light rotation is working, Moving object is not working, rotating object is working;
   and in both cases, deformers don't work.
   here is a screen capture:
   https://www.dropbox.com/s/nvckyml24lzzjj8/Desktop%202023.02.10%20-%2013.01.34.01.mp4?dl=0
   this is the moment I hit the wall - is there any solution to resolve this problem?
   I'm asking because I will use it on animated characters.
   thank you for all your help
   All the Best.

Hi,
I solved my problem getting "shadow to vertex map"
It's not perfect but it is in real time and that's enough for me for now.
I modified a little bit of your expresso and connect point normal to plight normal.
https://www.dropbox.com/s/onj94slaskbw57t/07.png?dl=0
I hope it's not a bug
Thank you for all your help
I will test it with a shader and post some results.
Best regards

Thanks,
Have a nice weekend.

Hi,
I will post new questions in new threads in the future. sorry for the mess.
Thank you for your time explaining what is possible.
best regards
Michal

Hi Dr. Sassi,
Thank you for your quick reply.
I have another question based on firestone. I will also post some screenshots to make it clear.
I'm trying to replicate the shader from Cinema 4d standalone Halfton pattern. In this shader, you can set the gradient ramp dependent on the camera or light source to get shading.
where is a shadow the dots are bigger and where is light they get smaller. there is of course node (in Octane) "toon ramp" but it can be plugin only in two places
and you can't use it as a gradient mask to set the size of the dots. The dots just decrease opacity but not size. As in this example:
https://www.dropbox.com/s/0bk0yo0iz4e65ie/05.png?dl=0
Think I'm close. I was able to fake that using OSL Shader which supposes to get a light vector but it didn't work.
It can only give an object normal based on position so I move the axis point of an object to the position of the light.
And It works but only if the object and light are static.
https://www.dropbox.com/s/95e3xsitjgtl7xz/01.png?dl=0
https://www.dropbox.com/s/jfkftwoet704mei/02.png?dl=0
I need it to be dynamic. So baking is not an option.
We're getting to the point where I thought vertex map could save me.

Your method from the topic https://www.cineversity.com/forums/viewthread/2374/ is promising but I have one last question
Can you set the vertex map so that if the point normal is between 0-90 degrees to the light source the vertex is 100% strength and if the angle is from 90 - 180 degrees the strength of the vertex map is 0%
I hope my English is sufficient to make it clear

What I was able to do is to set the linear fall of the light to get this effect but of course is not working with complex scenes. And it's working more like a 3d linear gradient that you can set manually.
https://www.dropbox.com/s/jl2blo8l3wf35h1/06.png?dl=0
Thank you.
All The best
Michal

Hi
Is there a way to transmit shadow information from a light source to vertex map? Phyton or expresso?
Like in this plugin:
https://cinemaplugins.com/c4d-plugins/topology-vertex-maps/
But this plugin is unsuported in cinema 4d 2023.

I need this to create shader inside Octan.

I tried this method:
https://www.cineversity.com/forums/viewthread/2374/
but it’s not working as I expected. It illuminates the entire object if it’s in the light range.
Thank you for your help.
Michal