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View Full Version : 32-bit Z-depth using 'Luminance Depth' Preset


drossxyu
06-01-2008, 01:50 AM
Is this at all possible? I've tried rendering this pass with Mental Ray after setting my primary framebuffer to RGBA[Float] 4x32 Bit and my file format to 'TIF'. When I open up my images in photoshop they are indeed '32-bit', but the info pallete seems to report values in an 8-bit range (0-255). I know there are alternatives to the 'luminance depth' preset ( zDepthDOF, etc.), but I'd really like to get this method working.

-f

beaker
06-02-2008, 03:40 AM
Photoshop reports everything as 0-255, 8, 16, 32 bit, etc... Why, I guess so they don't piss off old time photoshop people (which is a really stupid reason). They should be using 0-1+.

Bitter
06-02-2008, 06:11 AM
Try regular z-depth from mental ray, it is 32-bit and correct, unlike Maya's odd z-depth.

drossxyu
06-02-2008, 08:41 AM
How do I go about using Mental Ray's Z-Depth? Unfortunately, I'm using After Effects, which as far as I know, can't access an embedded Z channel.

kjaft
06-02-2008, 08:46 AM
There's a mental ray depth shader: http://homepage.mac.com/bauer/portfolio_shaders/zDepthDOF/zDepthDOF.html

Libor
06-02-2008, 12:25 PM
I think that its just bad settings in PS (navigator pallette) you have to switch display float values instead of 8bit 0-255 (default) its rather dumb from PS that it doesnt do it automatically when you load different bit depth imgs...

so just a settings thing it is in 32bit float.

beaker
06-02-2008, 02:51 PM
I think that its just bad settings in PS (navigator pallette) you have to switch display float values instead of 8bit 0-255 (default) its rather dumb from PS that it doesnt do it automatically when you load different bit depth imgs...So where is that at? The navigator pallette only has "pallette options" which only has a "view box" option. There isn't any display float options in there.

Emil3d
06-03-2008, 04:01 AM
Open the Info palette (F8) and then then click the little eyedropper icon in it.

DizzyJ
06-03-2008, 05:32 AM
I don't suppose there's any way to set the color pallet to 32float? There are time when I'm painting an incandescence map and what >1 values and have to cheat by setting white to (1/my highest desired value) and then multiplying in Maya to restore it to what I want. But that makes for a suboptimal workflow.

beaker
06-03-2008, 03:48 PM
Open the Info palette (F8) and then then click the little eyedropper icon in it.That's about as hidden as you get. Good to know. Too bad that is the only place you can see exact 16 or 32 bit numbers.

DizzyJ
06-03-2008, 05:19 PM
That's about as hidden as you get. Good to know. Too bad that is the only place you can see exact 16 or 32 bit numbers.

It gives you 3-decimal precision and shows you the >1 values. I opened up the uffizi probe to check values: the brightest parts of the sky are >15.000, while the white on the marble at the center, just under the sky is in the 1.000-1.100 range.

To answer my own question, the color pallet can't give you >1 values, but if you click the color picker in 32 bit mode, you can control intensity (measured in stops), which allows you to paint in >1 colors. Most of the tools don't work in 32 bit mode, but if you can use paths, it should allow for some cool things.

drossxyu
06-03-2008, 06:10 PM
Awesome, you're right about the color picker. It definitely reports values greater than 1.

Unfortunately, I'm still not able to get an adequate depth pass out of maya (without using the ZDepthDOF shader).

Is the 'luminance depth' render layer preset only good for an 8-bit
Depth Pass?. From what I've tried so far ( with compound blur in after effects ), the 8-bit depth pass looks horrible. Is it my pass, the effect, or a combination of both?

Als
06-03-2008, 06:11 PM
Could this help:
http://www.cinepaint.org/


Als

Emil3d
06-03-2008, 09:13 PM
It gives you 3-decimal precision and shows you the >1 values. I opened up the uffizi probe to check values: the brightest parts of the sky are >15.000, while the white on the marble at the center, just under the sky is in the 1.000-1.100 range.

To answer my own question, the color pallet can't give you >1 values, but if you click the color picker in 32 bit mode, you can control intensity (measured in stops), which allows you to paint in >1 colors. Most of the tools don't work in 32 bit mode, but if you can use paths, it should allow for some cool things.Well, no HDR Color palette yet in PS but you can create a whole range of HDR color swatches. Although it is hard to imagine how practical it is to paint HDR images from scratch on a monitor that can’t show the entire range at a time. You have to constantly drag left and right the exposure slider from the 32 bit preview options in order to see what you are painting. It is more practical to paint retouch on a small scale existing HDR photos, rendered images, and 32 bit textures that were converted after created in 8 bit.

By the way I don't get what you mean by “but if you can use paths, it should allow for some cool things” Can you please explain?

jaygarrison3d
06-05-2008, 09:24 PM
Awesome, you're right about the color picker. It definitely reports values greater than 1.

Unfortunately, I'm still not able to get an adequate depth pass out of maya (without using the ZDepthDOF shader).

Is the 'luminance depth' render layer preset only good for an 8-bit
Depth Pass?. From what I've tried so far ( with compound blur in after effects ), the 8-bit depth pass looks horrible. Is it my pass, the effect, or a combination of both?

I'm pretty sure that if you have a good luminance depth set up that you can render it with Mental Ray at 32bit. Catch is you have to use "Tiff Uncompressed" or "EXR" also be sure to set your mental ray "Primary Framebuffer" to RGBA [float] 4x32 Bit. I just did a quick test and it spit out a 32bit tiff that photoshop could read.

I can't promise that the data had 32 bit level of detail, i'm still new to photoshop handling 32bit, but I checked the historgram and it seemed pretty healthy. Spread throughout the black to white range, no stairstepping or gaps.

Anyway, you might give this a shot. I do hate that it's so hard just to spit out a basic z-pass like everyother renderer on the planet. :-/

Bitter
06-05-2008, 10:19 PM
I've not had an issue recently. 32-bit float framebuffer, RGBAZ filetype like EXR or .iff. Hit the check box for z-depth in the common settings and the box to pass custom depth and voila, zdepth for Shake that's correct.

That's easy enough it seems.

The problem seems to be Photoshop.

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