cool hope it’s possible.
The general idea is to have anything (a new kind of reverse lamp for ie) that can scan if it receive direct source of light or indirect lighting from surrounding meshes on which light is hitting (ambiant lighting). For that one, any mesh with baked light texture would be enough to trigger the reverse lamp.
Like any lamp, it will get a range and parenting it to the character so it gonna scan all the time surrounding lighting or baked light textures
The goal with that is that when your character is in a cave , the exterior environment lighting will have no more effect of the character mesh and it will be all black… By now, exterior environment lighting is always there no matter if it’s 200 feet under ground
! that parameter set to 0 makes the material desensitized to environment lighting only but not to other source of lights … which is very cool.
related stuff but with a ray (and not lamp)
the lamp would be superior as it would affect each point of shader and not only the object as a whole