Hi,

Is it possible to render multi-channel exr files using Mental Ray with Maya 2008? I would like to include render layers, like diffuse, reflection and occlusion into my exr file for compositing. If this is possible, can you please explain or point me to some documentation on how to set this up. I am new to using Mental Ray. 

Thanks,

Wes

Wes McDermott | 3D Artist | Author
http://the3dninja.com
http://the3dninja.com/blog

I am also doing some R&D on the open exr format and have not been able to get any straight answers. Basicly I want to be able to render an exr file sequence in mental ray with the following passes.

main beauty pass
diffuse
specular
reflection
depth
motion vectors
occlusion

1) How do I set this up in maya2008SP1 ?
2) What frame buffer should I be using??
3) any other suggestions before switching the pipeline over to this method

Thanks guys!!

I’ve been kicking the tires on EXR myself.

I Thing there was a 3rd party Mr Shader called “megaTKpass” but I think it doesn’t work anymore with maya 2008

Arch . Tay A. Othman
Architect & 3D Artist..

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There’s a beta compile from puppet.

http://www.puppet.tfdv.com/download/shaders_p_e.shtml

I’m not using it, tho. I’m using the old shader from the beta shader section @ lamrug.org and the framebuffer writer @ http://www.writingshaders.com/framebuffers.html.
-
It’s not difficult. Just sign up and I could send you the compiled shaders for maya 2008-linux 64

maya 2008 can write multi channel exr.

I downloaded the puppet shader and have managed to get a multi pass frame out but I still havent been able to get all the passes into a single EXR. I have a few questions about the puppet shader set too. I have provided an image of my rollout also because my settings are looking strange (values are based on 1-4 and not TIFF, EXR and so forth.) making life very hard… =(

1) Can I use mental ray + maya shaders or am I restricted to using only the megaTK_Shader in order to extract what I want?

2) how do I get all the passes into a single exr file and not 8 or so diffuse, reflection blablabla… files

3) Is there a built in maya procedure to do this method without using the puppet shader set??
(not to say the shader does look very nice but what if I have written my own shader and want passes from that?)

	Attachment

Andrew@Resin 12 May 2008 11:39 PM

1) Can I use mental ray + maya shaders or am I restricted to using only the megaTK_Shader in order to extract what I want?

2) how do I get all the passes into a single exr file and not 8 or so diffuse, reflection blablabla… files

3) Is there a built in maya procedure to do this method without using the puppet shader set??
(not to say the shader does look very nice but what if I have written my own shader and want passes from that?)

1- maya doesn’t have any shader to extract multiple channels to one exr file. Not in the geometry shader way and I don’t know if you can do that using the maya’s framebuffer mechanism (you know, the one using the camera and render globals). So you’re restricted to using puppet’s MegaTK or write your own.

2- use the same filename (instead of diffuse_pass.001.exr specular_pass.001.exr… use the same filename for all the passes like multichannel_pass.001.exr).. I don’t know how to do it using puppet’s shader. Better take a look at the readme files or ask him.

3- no. The mental ray shaders like mia_material_x and some others define their outputs using strings, but maya doesn’t support this yet.

I don’t know how to use the ctrl_buffers and that stuff.. i’m using linux.

I managed to get an exr file out with the passes I needed and fixed my attributes editor rollout so thats really cool but im not set on this puppet shader just yet. I have used it for 2 days in production now and already I have hit a roadblock with its features. I am curious as to how bigger studios are using the EXR style workflow and are they using the puppet shader to do this??

Anybody out there please share some info with us!

PS.
Autodesk should really hop on and get this feature supported with MR.

well i just cracked it from ctrl buffer…
its a nice shader .. hope you all have heard about it ..
leme know if you guys want any details will definitely be happy to help u all out ..

Sushant S Acharekar 16 May 2008 09:43 AM

well i just cracked it from ctrl buffer…
its a nice shader .. hope you all have heard about it ..
leme know if you guys want any details will definitely be happy to help u all out ..

Awesome! I’d love to hear how you did this.

Thanks,

Wes

Wes McDermott | 3D Artist | Author
http://the3dninja.com
http://the3dninja.com/blog

the tutorial follows…