Weierd Lighting Boundaries in Turning Objects into Lights

[Popaulol]

I am currently in the chapter on adding Lights in Raytracing: The Next week, and i am seeing this weierd lighting boundaries, both with BVH being used and without it.

My Code: https://github.com/Popaulol/RustTracer

[Popaulol]

(The Light gray boundary comes from my ppm viewer)

[hollasch]

Looks like your front face is pointing in the opposite direction.

[Popaulol]

Shouldn't that not matter since the plane emits light on it's entire surface?

But I'll try that out once I get back on my PC