Transparent Parts Incorrectly Cause Scenes To Be Over-Exposed, Interferes With Bloom


So, here’s a scene as it looks normally. Note the room is currently nearly pitch black, and you cant make out details.

Now here’s the exact same scene, but a block of light blue, partially transparent, smooth plastic is placed infront of the camera:

Woah! What the heck happened?? It now looks extremely brightly lit, and rather over-exposed. Now think about the physics of this - a transparent piece of blue plastic cannot brighten the scene itself, it is only able to block light, in this case red and green, from passing through it, so in no circumstances should looking at a scene through a transparent object make details, such as the pattern of light leaking in the ceiling here, that are unable to be made out normally due to being unlit, suddenly easy and clear to see. You don’t look out your window at night at suddenly find out you can make out the leaves on the pitch-black trees just because your window is between you.

Now this can be solved by making the block colour black, but now we have a new problem:
a) Black windows look weird
b) All the neon in the scene now loses its bloom effect when viewed through the glass.

These two issue combined create a catch 22 that ruins the visual design of the centerpiece of Innovation Arctic Base, and if it wasn’t for my colleague having already re-lit half the game for Voxel lighting, I would be returning to legacy.

(The bloom effect applies in reverse too - white parts exaggerate bloom which can also be problematic)

Edit 2: the difference is much more noticeable on my laptop than my phone!




Note the block on the far right is glass instead of smooth plastic. This behaves much more realistically, but only for people with a high enough graphics setting, otherwise it is identical to plastic.


You probably need to tweak the lights and lighting properties. This article might help:


Thanks for the article, but this is an issue specifically with using transparent parts, and these settings are not having any affect on that.


Changing the block color to black removes the weird brightness increase, but as a consequence also negates neon:


Now I better understand what is going on, I have rewritten this post to more clearly express the issue and why it should be changed.