Experience orbs become very dark when viewing them from certain angles

The bug

XP orbs become very dark when viewing them from above.

Additionally they become extra dark when the player is facing east/west

Reproduction Steps

• Throw a bunch of xp bottles

• Stay above them while looking straight down

• (Optionally) Rotate your camera so your facing is either 90/90 or -90/90

Observred Results

• The XP orbs become very dark

Expected Results

• The XP orbs would stay the same brightness