A quick little Gamma script

I said I would post some stuff and 10 minutes later, here I am (pats self on back) . . .
Working on a job recently, we were using linear workflow, which is sweeeeet, but not so shocking since this was a pretty big studio that does mostly photo-real work. But they actually didn't have any automated way to deal with the gamma correct nodes in the scene (that I or anyone I talked to knew about). I got to one scene that I was animating and went to do a rough mock up of the texturing and lighting and realized with all of the objects and references and such that there were 40 or 50 shaders that needed a gamma correct node. So I decided to just write a quick script to do it. I know there are versions of this kind of stuff out there already, but if it's something manageable, I prefer to do it myself. I feel like I learn more that way.

Turns out, it's actually kind of hard to do scripting for this stuff. Basically, I just wanted 3 basic things. Add a gamma correct node right before the color slot of any shader I select (or all shaders), be able to adjust those nodes (turn the gamma from .455 to 1 and visa versa) and be able to remove all the gamma nodes if I want to. What turns out to be really tricky is navigating upstream/downstream from the selected materials. If I wanted to put a gamma correct node somewhere upstream from the selected shaders I would have to traverse back up through connections recursively and run the risk of encountering loops and such. Basically, navigating through shader trees is trickier than objects, because without the DAG hierarchy (parent/child) there's not such a clear and definitive relationship between nodes. I'm sure it's doable, but started getting deeper than I was interested in going, so I simplified things.

I wrote a script that will look at the "color" channel of a shader (I did blinn, phong, anisotropic, lambert, surface shader, mia, mia_x, mia_x_passes, testing for their respective color channels) and look for  a gamma correct node connected there. If there's not one, it will add it with the values you input. You can choose materials to apply this to, or do it to all of them. If there's nothing going into the color channel, no gamma is created. You can then adjust or delete the gammas (again only the gammas connected to the color channels) from the other tabs in the UI.

Basically, as long as your only worried about color information connected to the material and you're not adding any gamma correct nodes elsewhere in the tree, this script should cover you. Just run the scripts (zbw_gamma) select the materials you need gammas for (i.e. blinn, mia_material_x_passes, etc) and use the buttons/tabs to add, adjust or remove them.

As usual, I make no guarantees about how it will work for you, so don't plan on funding your retirement by suing me. (Like I've mentioned before, part of my reasoning for posting these scripts is just so that I have access to them if the studio I'm at has locked USB ports or something. Easier than emailing them to myself every job :)
Oh, BTW, I know there is some pretty useful gamma stuff in 2011 now. I've only been at 1 (!) studio that uses 2011 in production. And that was pretty hairy. I'm sure more than that do, but 2010 is still the most common release for use in production in NYC as far as I can tell. Any studio that has any significant pipeline tools, render farms, etc, would have to change/update all the code to incorporate 2011 into the pipeline and I'm not sure it's worth it at this point (actually, it's obviously not worth it yet, the proof is in the pudding, as they say)
Anyways, happy gamma-ing!

 You can download the script HERE.

Been a while . . .

Wow. It's been a loooooong time since I've posted anything. Been really busy, moved apartments here in NYC over the Christmas break (on rather short notice, I might add, but for the better), did the holiday/insane blizzard thing and have basically been working crap-loads ever since the new year. But I have a day or two off and plan to get some more material up here in the next couple of days. Maybe some videos on some things I've been using for work and some new stuff that I've been learning about. 

BTW, thanks to Stuart Christensen for pimping the blog-izzle. He's got a you-tube channel where he cranks out tons of great tutorials on maya related stuff. Check it out at http://www.youtube.com/user/deepfriedectoplasm. Kind of bananas how many tutorials he does. . .

Anyhooo. I'll be back soon with some stuff to show.

Setting up a "Reverse Foot" Rig

Creating a reverse foot setup is fairly simple (that's the thing that keeps the character's feet stuck to the ground and allow you bend the foot in various places). But the process can seem a bit complicated when you first see it . . . lots of moving pivots to various places, etc. So here's video to walk through how I do it. Obviously, other people have other ways of doing it, but let's see them make you a video! They'll never love you like I love you! {sniff}


Maya/Rigging: Reverse Foot Setup from zeth willie on Vimeo.

Set Driven Key weirdness in Maya

I noticed this issue a few years ago while animating something (something brilliant, I'm sure) and realized while describing it recently that most people don't actually think about the "behind the scenes" stuff when creating set driven keys. So here's a video describing it!
In short it goes over the "interpretation" graph that gets made when a set driven key is created and how the tangents (and shape generally) of that curve affect your animation.
Please to enjoy . . .

Maya/Rigging: Set Driven Key Animation Problems from zeth willie on Vimeo.

Modeling for animation - 3 part video

Did you know that the word modeling has only one "L" in it? For some reason I always chuckle when I write that. (as opposed to "sepArate" vs. "sepErate", which my brain seems incapable of ever remembering).
Anyways, more to the point, here are a few videos about MODELING (heh heh) that go over some basic stuff that pertains to animation. Did these quite a while ago and forgot to put the Vimeo links here on the blog. Oops.
These go over creating and using edge loops to get the forms you want while keeping the poly count low, localizing additional geometry you're creating using loops, and some general tips about modeling for rigging. The general idea of all of these is to point out that modeling for animation and production has some different requirements/goals than animating for, say, stills or for turntables. Some of the stuff is pretty basic, but things that I see done a bit wonkily fairly often, so there you go . . .

Modeling for Animation - part 1 from zeth willie on Vimeo.

Modeling for Animation - Part 2 from zeth willie on Vimeo.

Modeling for Animation - Part 3 from zeth willie on Vimeo.

Creating custom render passes in Maya & Mental Ray

Been studying up on how to create some render passes in Maya/Mental Ray. I'm using 2008 (so sue me), but this should mostly be applicable to 2009/10, as well, because there are some issues with the render passes coming out of both of those versions (mostly much longer renders, as Sagroth talks about HERE).
Basically the idea is to use the mia_x shader in particular to get a full spectrum of render passes basically at no cost (or little cost) to the render time of the images. This can be HUGE when you're rendering a longer animation or a series of animations.
Problem is that it's REALLY complicated, so I do it in three parts here. Part 1 talks about why you'd want to do this, Part 2 talks about the basic setup in Maya using the SimplePasses shader (which you can download HERE) and Part 3 talks about adding multiple shaders to your passes (both multiple mia_x and other custom passes) and some things to look out for re: render layers.
BTW, the script I'm using in the vids is here, though I make no promises about it. I fixed a couple things and can't replicate the weirdness from the 3rd vid, so I think . . . think . . . it should work OK for most things. To use it, source it, then type "zbw_renderPasses". If you open it in a text editor, there are some basic instructions in the header . . .
So anyways, here are the vids :)

Maya/Mental Ray: Custom Render Passes (Maya 2008) Part 1 from zeth willie on Vimeo.

Maya/Mental Ray: Custom Render Passes (Maya 2008) Part 2 from zeth willie on Vimeo.

Maya/Mental Ray: Custom Render Passes (Maya 2008) Part 3 from zeth willie on Vimeo.