@emotion-police
...I'd like to know, is there a way to replicate the function of a Lumas shader in the material nodes?
The Lumas shader is Light Based and NOT GI based. It will only react to actual light objects.
Unfortunately, the New Nodes won't support dragging Objects (including Lights) and using their position to create an equivalent to the Lumas Shader.
Your alternative is to use the old Shader Graph (XPRESSO Nodes) and create a material with Only Emission, and drive that emission using a few nodes:
- Drag any lights in your Graph and get their Global Position.
- Using a State Node, get the Normal output (the direction of the normal at every rendered pixel) and do a "Dot Product" with the Light's Global Position.
The dot product of 2 Vectors (normal and Light Position) define the "Perpendicularity" of the two vectors. So if the Normal is pointing towards the light, the product is higher (brighter), while when facing away, it's darker. The result of a Dot Product is just a plain number and NOT a vector.
- Using a "Change Range" you can define the smoothness of the falloff.
In the attached scene I have used 2 lights and I'm using a Color Layer to mix the result of the 2 calculations by controlling the Mask for each color. The Layer color defines the color of the light.
Although not perfect, it may get you closer to your goal.
https://www.dropbox.com/s/zj5ng9rnp2vvg4w/Lumas%20equivalent%2001A.c4d?dl=0