2007-10-26

Production Shaders: "Hidden Treasures" of 2008

May I present to you, the "production" shader library.



What? Where? Production shaders?
Well, here's the story:

The Hidden Shaders


If you have installed 3ds Max or Maya 2008, you will have obtained mental ray 3.6, and with mental ray 3.6 comes the production shader library.

However, in neither of Max or Maya are these shaders exposed by default to the end user. They are hidden, and therefore "unsupported".

Still, they are there, and they can be used. But to do so, one must first "unhide" the shaders.

Why "hidden"


Simple matter of resources of Quality Assurance at Autodesk. The shaders has not gone through enough torture - yet - to be signed off by QA as "officially supported". But that's where you, my adventurous mental ray addict, come in! Consider this an extremely public beta, if you will....

How do I "unhide" them?


Unhide instructions for 3ds Max 2008 are here

Unhide instructions for Maya 2008 are here

What are they


The production shader library is a set of tools, some simple, some complex, to aid in doing production rendering, i.e. in a visual effects context.

There are two basic categories of shaders:

Simple
First we have the simple utilities like applying a gamma to a color, or giving different results for different "ray types" (reflection rays, transparency rays etc.). These shaders are very simple, and you probably have found similar shaders online before. These shaders are not better than those other shaders that do the same thing, they are simply a standard set that now ship with all products. I.e. "mip_rayswitch" isn't terribly different to Control Studio's "ctrl_rays", but you don't have to install anything to use it.

Advanced
Then we have the more complex shaders, such as the 2.5d motion blur shader, or the matte/shadow/reflection system used to cast shadows (and reflections) off of a stand-in object in your scene, for integrating CG objects into a background plate.

A lot of examples of the mip_matteshadow and other production shaders are available as a small demo movie constructed for siggraph, it's available as YouTube as well as WMV, QuickTime and DivX versions.


What do they do?


The main intent is to simplify the workflow of compositing CG objects into background plates, and other visual-effects related tasks that one may run in to on a daily basis.

In some cases they exist to give a simple workflow to a simple thing. For example, the mip_cameramap is a simple camera mapping shader that simply projects back an image from the render camera (and only that camera) "into" the scene 3-dimensionally (unlike, say, mib_lookup_background, Max's "Screen" mapping, or similar).

There are more complex "camera projection" shaders out there both for Maya and Max that can do similar jobs, but at a slightly higher effort. Again, the logic here is to provide the simple tool that can do the job, and if you need the more advanced feature, use the more advanced feature.

Similarily, the mip_mirrorball shader is for a simple unwrap of a mirror ball into an environment map when taken from the same camera angle as the background plate. For anything more advanced you would probably have to unwrap the mirror ball image in some unwrapping software and apply as a spherical map... or maybe you are a high-end user that uses SpherOn cameras and don't even use mirror balls... then ignore this shader, use your more powerful tools.


Mark my words, I will be posting quite a lot on the topic in the months to come, but meanwhile you can read the PDF documentation. In Max, the names of the shaders will appear slightly different than in the manual, but you can figure that our rather quickly, I hope.

That's all I have time for for for now:

Stay tuned to future blog posts on the subject.

/Z

28 comments:

César Sáez said...

Hi Zap, first of all thank for all the tips than you put here in your blog, are really helpfull for all us mental addict :)

My question is a little offtopic, is about the relationship between mental ray and Softimage, do you know if these new features and some arranges of UI like the new exposure control of max will be avaliable for XSI 7.0 when it be ready?

Probably the shaders (just like the architectural) will be in XSI but what's about the mr exposure control, is exclussive of 3dsmax/Autodesk or it come from mental ray? anyway... is just a new ui for simple tone mapping or is really a new feature?

Sorry for this little offtopic and for my poor english.

Thank in advance :)

HJ said...

Jaså det var så man fann den omtalade production shadern.

Thanks for making this available.

/iduna79

Master Zap said...

The "exposure" is purely a mental ray thing, so purely hypothetically it can be a part of XSI as well.

If it actually will, and when, I can neither confirm or deny etc....

/Z

José Miguel said...

These shaders are totally awesome!, simple pipeline for complicated things, I like it.

ray said...

Some info for xsi users

http://www.xsibase.com/forum/index.php?board=12;action=display;threadid=33345

Master Zap said...

Heh, I love how industrious you are, my lovely mental ray users.

Although a warning; the XSI thread claims that it runs from "3.4-3.6.99" or somesuch.... this isn't true, it will most certainly break on ray 3.4 in most cases (data structures are laid out differently, shaders compiled for 3.5 or above can break under 3.4 and vice versa.... if those struct items are accessed... which they are in the production shaders)

/Z

ray said...

3.6 mia_material's backwards compatible interface hangs xsi's 3.5 mr. Is there at all a chance to get this working with 3.5?

krs said...

Neat Stuff ,

How I apply the 2D/2.5 motion blur shaders in Maya ? Maya never seems to make docs for many MentalRay for Maya features .

Does it work in all modes ( Interactive rendering , batch , standalone ) ? Does it require any special render globals settings ?

Thanks

Wilbert van den Broek said...

Hey Zap Thanks for all the great tips!

I've been working with the sample files mip_matteshadow1 & 2 in Maya and when I render it with my own objects and background image I get a realy weird result.
It seems like some of the rendertiles are rendered without the background and with incorrect lightning.

Do you have any suggestions?

Thanx in advance

Wilbert van den Broek said...

Here's an image of the problem I described. Forgot it in the previouse message.

http://www.flickr.com/photos/wilbertvandenbroek/2402475937/sizes/o/

Master Zap said...

Are you using network rendering (Satellite/DBR)?

If so, either
a) the shader isn't loaded correctly on the slave host or
b) the image can't be reached by the slave host

/Z

Wilbert van den Broek said...

I'm rendering on a single machine so that can't be the problem. I've tried everything else (reboots, deleting my docs/maya, starting with fresh new scenes) and so far nothing works.
But when i delete some objects the problem dissapears.

http://www.flickr.com/photos/wilbertvandenbroek/2402555699/sizes/o/

Don't know how to solve it so I'm going to start modelling it again.

Lisandro said...

Hi Zap! Since matteshadow doesn't cast masked shadows ("The opacity does not apply to the shadows or photons"), how could you make a matte material cast masked shadows?
Supose you are using a cylinder as an arm, and you use the arm opacity to refine the shape as an opacity map, how could you make the cylinder cast properly shadows (with the arm shape) ?
Thanks in advance!!!
Lisandro.

thor said...

Great post !
can u publish again the pdf documentation please

VMG said...

Hi Zap, first thanks for this great post, now the question have you used the ENV_Sphere node piped trough the MIP_Cameramap node instead of using just an plane image? this case you can have a 360 camera movement from one nodal point or have you had a similar aproach on how to do this

thanks

tecnet said...

Hello, Master Zap.
Is it possible to use HDRI like these: http://www.hdrmill.com/Freebies.htm with the production shaders?

kevin said...

Man, I was so pumped to do this tutorial and finally find a HDRI sky solution. However, I tried making the adjustments to the file in max 2009 design and totally screwed up max when I restarted. It is fine now since I saved an origional verion of the file but I am really bummed about not getting this to work.

Koddy said...
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Sasa said...
This comment has been removed by a blog administrator.
djtlumic said...

Hi Zap, first of all i wanna thank you for great tutors and explanations.i hope this is not too much off topic, but i have XSI 2010 with scene with production shaders(even scene from DT production sharers have same problem).mip_MatteShadow shows all white in alpha and background is white too.i am not master in XSI :) im quite lost,because i cant composite :( in max there is alpha transparent button or something like that,in xsi not. just force TR alpha in mip_cameramap.can u pls advice or direct? Tnank you again,u r the man ;)

djtlumic said...

yes. i found it here http://mentalraytips.blogspot.com/2007/10/production-shader-examples.html in examples for maya...thanks again ;)

saim said...
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Abby said...
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Farrah Khan said...
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x aucian said...

Very informative. Thanks.