Once I was just playing around with stuff, when I looked through the camera and saw this:
I've always wanted to make my renders 3D glasses compatible. Yay! The problem is, I don't know why that happened or how to replicate it. When I look outside the camera, the effect goes away. (Also, will it show up in the final render?)
As soon as I started rendering it, I noticed a little icon in the header of the UV image editor.
It's highlighted in orange and looks like a camera with two lenses.
I found out! It's in the render layers tab under the views panel.
