Not correct. The Z-depth in maya is 16 bit. The reason ppl think it's 8-bit is that if you open an .iff file in photoshop (using the .iff plugin), it will crunch it to 8 bits and do some other nasty things to it too. Also the Z-depth is not supposed to be antialiased because that would cause incorrect depth info. The trick is to mask the z-depth with alpha...Originally posted by Renderizer
Hmmm...a little bit late, I guess...anyway:
Over at Highend3D, you'll find some shaders to render out a separate z-depth pass. Maya's z-depth is 8-bit only, so it comes out aliased. With the mentioned shaders, you'll be able to render the depth info ito 16 bit image files.