I ran into an issue today where I wanted to set a lamp to only affect one object in my scene. I found a workaround in Eevee that did the trick nicely. I set the lamp to have a custom distance, just long enough to light the objects I wanted to light and nothing else. I then decided to go with a Cycles render and tried doing a similar technique using the “light falloff” node. I couldn’t get a satisfying result so I went back to the drawing board and decided to look into “exclusive lighting” to stylize my lights. I found that I can set up render layers to achieve this effect, but it is a somewhat involved process and would get messy if I were to use this technique for a larger scene with many stylized objects such as a cartoon or cel shaded animation.
The ability to include/exclude lights from either a collection, object, or material, would go a long way to give more creative control to the artist. I understand that Cycles is a photorealistic rendering engine but, with the absence of Internal render and the technical limitations of the Eevee lighting system, it only makes sense to add more NPR options to Cycles for use cases like this. This is not the first time I’ve needed to do something like this, and from my internet browsing, I don’t seem to be the only one missing a feature like this.
Hopefully we can one day have a lot more control over our lamps so we can more easily achieve results like this: Guilty Gear GDC - “Controlling the Lighting” (via YouTube). Would be great to see this in Eevee, too, considering it can be done in other game engines such as Unreal Engine.