Thanks for the quick response, Stella!
Edit: Can ignore what I wrote below. I got it working! Setting back light to 0's, back light direction to 0.5,0.5, and feeding key light a dynamic position did the trick. Now I have a 'night' version with dynamic light sources that I can place where needed.
Thanks for this awesome system! Already tested on a fixed with 3 independent objects and also programmed dynamic shadows to follow my mouse cursor as the light source for testing. Everything is working perfectly. ^^
I have been coding shadows myself dynamically, since those are easy, I can tie them to the object itself and change them relative to the light source. I actually don't need to go that far for what I am doing, though.
However, shader and rendering is something that lies outside of the displayable and I am still not quite certain how to 'apply transforms to an entire layer' the way you described using this system. I work with Alpha Masks and transforms just fine, but I don't understand how to apply the shader.
Let's say the shader I want is a radial light gradient for a torch that is 500x500 px radius (I have a PNG with this design on it). I want it centered on the torch which is located at, let's say an align of 0.5,0.5 (center of the screen for simplicity).
How can I feed the position and size of the shader to the transform relative to the screen? Do I define that in the transform itself, or do I need to use the system to register a new shader?
(Actually, a TL;DR simple case application might just be: How can I use this to make a radial light source follow my mouse cursor? If I can accomplish that, I think I can do the rest myself.)