Mental Ray 16bit

[digidrag]

I'm running:
Maya 7.0 on Windows XP Pro SP2
Mental Ray is version 3.4.5.1
AE 6.5 Pro
Quicktime 7.0

I have been asked to render some 16Bit images for use in a After Effects comp.
I can't seem to get a Uncompressed 16Bit image out of Maya Mental Ray renderer.

In my Render Settings>>mental ray Tab I have the "Primary Framebuffer" setting set to:
Data Type: RGBA (Short) 4x16Bit
Gamma: 1.000
Colorclip: RGB
Interpolate Samples: Checked
Desaturate: Un-Checked
Premultiply: Checked
Dither: Checked

What is the difference between:
RGBA (Short) 4x16Bit
&
RGBA (Half) 4x16Bit ?
I can't seem to find anything about this in the Mental Ray documentation.

The the Maya Docs I have read state that SGI, TIF, RLA, IFF, CIN etc.. image formats are supported by mental ray for rendering at 16Bit.
Yet I cannot get any of these to render out a 16Bit image. Through the Render View or Batch functions.
Also when in "Render Using>>mental ray" I am missing the .cin image format in my "Render Settings>>Common>>Image File Output>>Image Format" list. Yet the documentation for both Maya and Mental ray state that it is a supported mental ray image format.

I'm checking the images with:
imf_disp.exe
Quicktime
After Effects

The only image format that so far has rendered a 16Bit image (when checked with imf_disp.exe) is "TIFF uncompressed" but this file crashes AE on Import and Quicktime loads it as a 8Bit image.
Also it's not like Maya is rendering an Image that these programs just can not deal with (other than TIFF uncompressed) the file sizes have been very low. 40 - 1,000kb. A truly uncompressed HD1080x1920 file should be between 15-23Mb per frame.

Does Maya's Batch render function of Mental ray not support 16Bit file formats?
Do I need to install special additional codecs?
What file type are others using to get 16Bit images out of Mental Ray/Maya?
Do I need a special output shader attached to the camera?
(There are non listed in my hypershade's output shader category. In my Camera's mental ray tab there is an "Output Passes" option. It is greyed out but I can see that the color is set to byte. I cannot change this option. Do I need to or is this for pass based rendering only?)
Will I have to write a custom Output shader just to get a correct 16Bit frame? If so: Is there a Output shader library anywhere?
Is there some little preference checkbox I'm missing somewhere?

Help!

Thanks.

[digidrag]

Ok so after typing this long post I have solved one problem.
But that solution has brought up another question and didn't solve others.

I figured out that I can get Maya/Mental Ray to output a 16Bit SGI file that AE can see and use.
I did it by opening up the second "Output Passes" tab in my Render Camera.
I created a "mentalrayOutputPass1" set my data types, image format, etc.. and the Batch Renderer did output a SGI 16Bit image to my "renderData\mentalray" folder. But Maya also still creates a 8Bit image in the "images" folder.

1. Is this Output pass a framebuffer rendering the image in 16Bit then compacting it to write the 8Bit image in the image folder?
   In other words is Maya rendering twice (16Bit file then a totaly new 8Bit file)?
   Or just once(16Bit in the buffer and then converting and saving it to a second 8Bit file)?

2. Can I turn off the creation of the 8Bit file and only keep the 16Bit Output Pass? To help save storage space.
   Right now Maya is writing 2 files.

3. I still don't understand the (Short) vs. (Half) option.

4. Am I still doing this the hardway? Is there a better way to get Mental Ray to output 16Bit images?

Thanks

[joojaa]

you get 2 images because you ask for 2 images! Anyway probably why your tif crashes you is probably bacause your rendering out in half mode wich is a FLOATING point image wich AE does not support! There are basicaly 3 reasons whuyy i dont use AE and its the extremely BAD support for zdepth, bad support for flaoting point images, bad overall speed.

But yeah maya renders them simultaneously, so yes it does not render 2 times. Personaly i have not rendered out anything but oxr or tif lately so i havent noticed this lapsus. Well you can allways delete the primary buffer file in post render

Anyway i seem to recall you cant render out unclipped forms of non float formats so maybe thats the reason

[digidrag]

I know I'm asking Maya for 2 images.
But shouldn't it render (through the Batch command) a 16Bit image without me having to set up an Output Pass for the Camera?
So far non of the 16Bit supported file types have produced actuall 16Bit images when rendered through the "Batch" command.
That is my main concern.

Also I'm using the "Short" 16Bit and that was crashing AE.
Does "Short" stand for RLE compression or something?
There doesn't see to be any options on setting RLE compression or not setting it for the outputted file.

Are there any tech docs anywhere that mention the differences between "Short" and "Half"?
It seems weird that they would call something that is Float; "Half" and not just call it "Float".
I also thought "Float" was the term used for 32Bit images.

I understand AE is not the best composite program. On this project I am being asked to deliver my files for AE compositing by another person. So I don't have the luxury of a choice.
The way I have it running now will work. But I feel like there must be a better way.
Seems like Maya should be able to just output a 16Bit image without additional Output Pass.

Also there are three color clipping states in Mental Rays setup.
The image's color is clipped to RGB, Alpha, or RAW.
I was using RGB which should clip color channels between 0-1.
The RAW setting has the ability to produce illegal colors that some programs cannot read correctly.

[joojaa]

because its a half sized float (as opposed to float wich is two times ithe half floats size). Anyway havet had the time to chek. The intended purrpose is that you can render it out but there might be a bug somewhere. Havent tested, hbut alteast i personaly know you can do exactly this in 6.5 BUT not unless yoru smart enough to set clipping on.

Naming actualy comes form coputer science. Anyway wouldnt be the first time someone manages to get glitches in a prog. Im not sure hlf float tif is possible so it might do it in 16 bit anyway.

Oh and no i cannot find any mention of a promise mr can output cin files tough there is apromise it can read them.

Anyway if you cant do this any other way just add a after render script thet deletes the extra framebuffer no biggie. Besides i dont think one image will make any difference on you hd use. I mean i know a terabyte of scaci is expensive but its NOT THAT EXPENSIVE in reality unless you realy render out full feature films (lets face it if you have less than 80 g in your use yoru not realy working for production). Besides how many do ius realy render whole movies in one go.

[joojaa]

Its a glitch, it even exports teh definition worng to mi file. Someones appears like been sleeping on the job.

[joojaa]

Yuh the stupid thiungs reading the iff settings form maya softwares globals!

So this is what you do, set maya software to render into iff 16 save the file as maya software render. Then render in commandline and bam they render out 16 bit images and thu.

Now that i came here i seem to recall having actualy done this once before.

[digidrag]

Installing the Maya 7.0.1 update fixed the issue.

In the release notes on Alias's site there are a number of "rendering" issues that 7.0.1 fixes.

[fxnurbs]

hi,

I have exacly the same problem with mental ray 16 bits.
The only way i found is rendering in exr, but i am not sure that i am really in 16 bit or more.
It wrote float, but it is a strange format.
Shake read it well, but after effect and combustion have wrong colors when loading it

Is Open exr have really 16 bits (or more) how to be sure, i don't trust reading the float because it can have many passes in 1 picture so what's inside really ?

Jaz

[fxnurbs]

I did a test like you said with use iff 16 bit in maya software and rendering in batch with mental ray.
It works, i have the 16 bits

Your the boss !

i still want to know about the exr, iff somebody know

Thanks again !