The z-Buffer [X-View]
Stereo-Visualisation of how a depth map is being composed.
Rendered with global ilumination.
By the way, this is also a stereo-photo.
You can receive a 3D impression without any
glasses, just a sporty ambition is needed.
You cross your eyes like once in your childhood
while keeping an arm´s-length distance to the screen.
Both photos should appear as 4 blurry photos.
Now let your eyes snap back to normal - but do it slow.
In advance of this, the two photos in the middle will overlap
at a moment.
Remain at that point for a while and your brain
starts to realize that these two overlapping photos are
almost the same. The middle photo reveals its 3D effect,
while both outer photos stay blurry.
All of this is not even dangerous to your eyes, it's
more like reading a book backwards.
This method in pictures: