View Full Version : Zdepth Artifacts.

06 June 2009, 06:59 PM
Whenever I use a Zdepth with a beuty pass I get hard edges around my defocused areas. This is because i have a high contrasting Zdepth and this result is predictable.

My quesiton is how do i overcome this? I heard ideas that i should render out each object separately in the Zpass and thencomposite them? Im not sure how to do this. I really like to push my zdepth I was wondering if someone could please give me a hand in fixing this problem.

P.S im very new to compositing

P.P.S im using nuke and/or after effects

06 June 2009, 09:06 PM
im not sure what software you are using but in maya of houdini its quite easy to seperate objects into different passes. All you need to do is add them into different render layers for Maya. This may give you a better result. For a quick and dirty way that sometimes comes out pretty good you could try to blur your zdepth pass. It will make the falloff and edges a bit better for you.

Let me know if that helped and what packages you are using to do this. Nukes blur or soften node does a good job for the second case.

06 June 2009, 09:08 PM
im using maya and it does a nice job eparating objects using the layers, i guess im moreso asking about nuke, how to compose z-information, and if this is even the prefered technique to begin with

06 June 2009, 11:58 PM
NUke is great. There is a zblur node at your disposal and you can alter your zblur layer in many ways. Use a shuffle to shuffle the channel into ano0ther one (like if it comes in the red channel you can move it inot thhe zdepth channel. you can add a blur to the zdepth channel before processing it in the zblur node. you can even grade the zdepth channel to really push it if you need to. Anything is possible.

06 June 2009, 02:07 PM
Composite your foreground and background layers separately. Don't forget masks to cut out any overlapping elements from the other layer. Apply Z-blur to each layer with its own depth buffer. Put the blurred foreground elements over the blurred background elements. You can set up an expression to that both layers share the same Z-blur settings.

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06 June 2009, 02:07 PM
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