Cornellbox not enough bounce light

[Seelengrab]

Hello! I'm in the process of following the second book and got this very weird image as a result:

I've gone over all of the code (from both books) multiple times now but I can't find the problem :/ Does anyone have any idea about what's going wrong? What I can imagine is that the problem lies either somewhere in aarect and its bounce or in scattering, but no matter what I think up, I can't find it..

[Seelengrab]

And of course, right after posting I find out what's wrong - the outward facing normal in my hit function of aarect was wrong and always pointed to (0,0,1) 🤦

Now to figure out why it's so dark

[Seelengrab]

I solved the darkness problem as well - seems to have been caused by my laziness in writing three seperate hit functions that I combined into one with some compiler tricks. Lesson learned - always establish a ground truth before trying to optimize.