I have an emissive texture up against a wall. it's just a flat plane with a color set to the emission channel. At some distance, there is a sharp shadow line on the wall—but I don't see how it's physically possible for this shadow to be occurring, the line runs parallel to the light source all the way through the frame, and I'm wondering if it's some kind of render setting.
It seems like it's not actually a shadow line, because it doesn't show up on surfaces within this distance. It's like some kind of force field that changes the light beyond a certain distance.
What could be doing this? A bit new to things here.