Effect that shows the depth texture
What's the trick? How do you use it?
This shows the depth textures value in greyscale (requires layer to be rendered in 3d) but if zNear and zFar is really far apart it may seem to just show one colour as the depth difference between the objects in the scene may be really small, but that is correct.
It is not really intended to be used in a game, but for debugging depth related issues.