View Full Version : about z-depth for composition..

10 October 2003, 12:10 PM
Hello all,

I have a question about z-depth. Does anybody know how to fix the aliasing problem (of z-depth) in composition?
I want to use z-depth for composition, not to do only a depth o field effect...

Thank you very much!
P.D.:Sorry for my english... ;-)

10 October 2003, 01:06 PM
use a seperate z-depth movie/image sequence.

I know two ways to achieve this, first use fog and second use a z-depth shader (available at highend3d)

just search for z-depth and you will find some nice threads descriping this

10 October 2003, 09:38 PM
When you render a depth pass, use a 2X resolution , then scale down in composition. It would antialiase a little bit.
But I'm still asking about this

10 October 2003, 01:02 PM

I did the resize option inside fusion, but it donīt work.... the aliasing does not go away.... and I have tried the "depth shader" but when I use it as a z-depth layer, the jagged edges appear again!...

When you use a antialiased image as z-depth (to do a comp, inside fusion) ,you will get a jagged borders where the objects are intersectioned.


Maybe someone can explain to me, how to fix it.... :rolleyes:

10 October 2003, 04:43 PM
An accurate Z-Buffer Channel cannot be antialiased. The greyscale color defines the distance between camera and object. Antialising would change the color values, so the software would think the borders of the object are farer away for example. You would additionaly need a Z-Coverage Channel which would show you in a grayscale picture the antialiased pixels. The Colorvalues define how much of the pixel is foreground and how much is background.

How to make it in maya?

No idea :)

10 October 2003, 06:37 PM
You are right! atzfratz

That (z-coverage) channel it is possible to do in a lot of 3d softwares....but not in maya!

I will do the render in Mental .....

Thank you very much! atzfratz

p.d.: Sorry for my english again....

10 October 2003, 11:08 PM
z-depth file is not a raster image. The b&w image you are seeing is a representation of the Z information of how far away things are from the camera. It's really just a data file of numbers and you are just seeing an interpretation of that. You would have to change the Z to the rgb channel and then resize it, or just blur it in the compositor. Best bet is to use what iC4 mentioned.

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