afterFX & depth chanel(Z depth)

[lowkey]

you'll have to check the attributes of the camera you want to render and activate renderable as well as depth in the output settings.

then go to render globals and activate depth from there either. the rendered depth files will be stored inside your project's folder under renderData/Depth!

EDIT:
the image format of choice will directly influence, which attributes will be rendered in a separate file or not.

when using maya.IFF all information will be integrated into the image (RGBA+Depth).

using i.e. targa, Depth will be stored into separate files!

[webster]

As far as i know AFX supports zChannel with Softimage and RLA,

[lowkey]

.iff works fine too! you'll just have to interpret footage with pre-multiplied alpha on.

[Medicine Horse]

I just wanted to add if your using 3D channel extract from AE and you embedded your depth into an IFF, you'll need to set your black and white ranges from 0-1 to see anything. It took me a while to figure that one out.

-M

[Firas]

i opened the depth file (iff file) inside \renderData\depth,

but i cannt see anything.. its black.. so from where do i set the 1-0 range of colors?

by the way i open the file on fcheck and afterFX and both are black.

and whats the : depth Type ->closest Visible Depth & its Thershold ?

[dwalden74]

If I could just share my own experience here for a moment....

I´ve never been able to use real z-channels on a project. Because it inherently causes serious aliasing artifacts I have always resorted to rendering a separate depth pass (using the depth shader from Highend). This is only real solution I´ve found for creating useable depth passes.

Anyone want to comment???

:beer:
David

[Medicine Horse]

Um, for sure you want to make sure you can see your Z in F-check before trying to set it in AE.

To my understanding-and I could be wrong as I am relatively new to Maya-the closest visible would only help in defining a "frontal" or "rear" blur type.

I recommend looking at your F-stop settings and the Focus region scale value. Setting this from default to say .15 may help you get the right depth you need. I don't know the scale your working on so, I'm stabbing at the dark here.

And the black and white point I was talking about earlier is in AE. Effect/3D/3D channel Extract. Set the black to 0 and white to 1 I believe, I'll double check that for you now.

[Medicine Horse]

Yeah, I've written my own Z -depth shader based off of Highend's shader. It's really stupid that the Z depth layer isn't anti-aliased. Maybe we should start bugging alias?

[Firas]

oh.. i cannt understand that maya cannt render z-depth in right way !

i was dreaming of rendering object ID mask in seperate file, but now i dont think its possible :thumbsdow

can anyone write plugin for that ?

[beaker]

>>It's really stupid that the Z depth layer isn't anti-aliased. Maybe we should start bugging alias?

This is a limitation of a z file in all software packages. You cannot filter a z file in any package.

[syntetik]

abou that aliasing. I´ve solved some issues with bad aliasing by adding "Matte Choke" effect. And than I had no problem with compositing depth (from *.RLA files). I´ve tested 3d fog and DOF, both passed with Matte Choke.

Firas>> You could need this. For getting info about certain pixel´s depth, just click RMB (RightMouseB) at the the image and look at info. Very useful for adjusting 3d effects.

I remember my 3dmax times, there was more information, including object id, that could be written in single file, yeah. But I didn´t composite at all these times, I was "unexperienced" :)) heheh.

[Medicine Horse]

beaker- check out my latest work.

http://www.hybridmedicalanimation.com/pages/jjani_qt/hybridmitosis_qt.html

I made the DOF in AE from a clean antialiased depth layer rendered from C4D. It would be cool if Maya could do the same. There are workarounds but it would be a timesaving feature to have.

-M

[baby]

there is no problem of antialias with the z-depht !!!

as you can understant z-depht is an infomation of depht based on the grey level !!!!!

if you had antialias on a z channel, the information would be totally false !!!!!


check lenscare from flisfloucht !!!!

http://www.frischluft.com/

[Medicine Horse]

I used lenscare on this animation too actually.

[danyrey]

Originally posted by Firas
i opened the depth file (iff file) inside \renderData\depth,

but i cannt see anything.. its black.. so from where do i set the 1-0 range of colors?

by the way i open the file on fcheck and afterFX and both are black.

and whats the : depth Type ->closest Visible Depth & its Thershold ?

When opening .iff Files with fcheck, press z to view the z-channel.
I guess, depth Values are stored in floating point format.

[syntetik]

/// if you had antialias on a z channel, the information would be totally false !!!!! ///

I agree with baby :buttrock:

[braam]

I agreed with baby that z-dept is just dept information provided by Maya. With aliasing you could get purest information when doing DOF in AFX. For example: you have 2 pixels with 0 and 1 information respectively. With anti-aliasing you will have 0.5 for both pixels, because of filtering to get smooth result. It is not correct the information that you get!

Hope you dudes understand.

cheers
braam :thumbsup:

[alexx]

/// if you had antialias on a z channel, the information would be totally false !!!!! ///

100% agreed with the math and the idea behind it..
at least if you do a real z-composit you will get deep into trouble with an antialiased z-channel.

but i found, that using an anti aliased z-channel often produces less visible errors, than using a "regular" and non altialiased z-channel in post process.
this is true especially for depth fog and in most cases for DOF as well, since a "slightly" wrong fog or blur value at the anti aliased pixels is less visible than one that occurs due to the hard transition between a sampled point in z and the background..

usually i work a lot on the z-channel (i do shake mostly - but what i do can be done in AE as well afaik) before i use it to alter my images..
and usually i dont use the z-tools provided but rather do regular compositing and image processing with the z-files.
(like e.g. using the z zu multiply a color on the image to get depth fading or using a blur tool that is driven by the z-image).

thats only my 2 cents :)

cheers

alexx

[Medicine Horse]

alexx,

that's mainly how I use the antialiased depth info from cinema too. I use it's luminence value as a blur.

[alexx]

Originally posted by danyrey
I guess, depth Values are stored in floating point format.

yep they are..
btw.. maya has the stupid behaviour not to write the depth values from 0 to 1 but from any range to any range..
could be something like -0.000234 to 0.2388762 .. pain in the ass using these values in shake.. :) (ok.. there are some macros on highend2D.. i know:)
but that is the reason why i usually use the z-info just as a mask

cheers

alexx

[lowkey]

btw, is there a method of rendering z-depth only?

i tried to disable RGBA in the render globals while checking z-depth, but the output .iff got no z-buffer at all.

how about hardware-rendering? when i look at z-depth (using fcheck) everything seems to be fine.

the problem:
after effects (resp. lenscare) doesn't show any reaction, when setting it up as depth layer to control DOF! :shrug:

how to do it right?

[Medicine Horse]

I answered this in a post above but I'll repeat. You'll need to bring in your image or sequence use the 3D channel extract effect. Set your black point to 0 and your white point to 1. From here you can then try to use this layer for lenscare. If for some reason it's not working. You'll need to precomp this layer so AE can see the 3D channel extract effect when it's invoking lenscare. HTH.

-M

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