Showing posts with label Compositing. Show all posts
Showing posts with label Compositing. Show all posts

Thursday, August 11, 2011

Follow up some Linear Workflow stuff for Maya 2011 +

Been meaning to do this for a while, but never got around to it . . . And I got scooped a little bit! Derek Flood did a couple of short videos about this and lit a fire. Thanks Derek!
Anyways a quick overview (as quick as I can do it, everyone else seems to have a better grasp of the brevity thing than I do) of how linear stuff embedded in Maya 2011/2 relates to what you may have been doing before . . . not expansive, just pointing a few things out.
*EDIT* Derek was kind enough to point out some of the specific bugs/weirdnesses he's found in the comments. Check it out if you're interested!

Maya/Mental Ray: Linear Workflow in Maya 2011 from zeth willie on Vimeo.


HERE'S (rt click, save as) the updated zbw_gamma script that works by shader selection and sticks gammas into the color channels. You can also adjust any/all gamma nodes in the scene or delete them globally.

Wednesday, August 10, 2011

Creating a reflection "sheen" pass for your scene

Every semester I end up explaining this in a really rushed and half-hearted way to a bunch of poor students who are in my animation class. Rather than do that again, I finally wised-up and made a video about it. . .
Somehow my videos seem to get longer and longer, so I split this up after the fact and made two videos (it's like my inner self is telling me to do less videos and more text-y type tutorials).
The first video is the basic stuff for setting up a render pass that will give a nice shiny reflection pass for your scene (stuff like a cell phone or tv in a commercial) and the second chunk of it gives a few ways to customize this concept and make it a more reusable using things like RGB passes for various different reflections, etc.
This is something that is really useful to know how to do in production, especially for stuff like commercials, so hopefully I haven't made it tooooo loooong and boring . . .

Maya/Mental Ray: Rendering a reflection "sheen" pass - part 1 from zeth willie on Vimeo.


Maya/Mental Ray: Rendering a reflection "sheen" pass - part 2 from zeth willie on Vimeo.



BTW, HERE'S the script that I use at the end for pulling stuff out to a render layer with custom color overrides . . . (rt click, save as)

Sunday, March 27, 2011

Creating an inky bleed effect in Nuke with Time Offset

Here's a quicker tip/trick related to Nuke. A really cool time offset effect that's actually way more complicated than it looks. This time it was for a job I was actually on, though we didn't actually end up using it for the final, as far as I know.
The gist of the technique is to use a time-offset node to take a frame that has literally just been written an instant before, add some effects and merge it back into the frame that's about to be written. So you get a cool trailing effect that iterates on itself, anything in the past growing while keeping a tight "leading edge". Not too crazy once you've seen it, but pretty hard to explain.
Anyways, Andy Jones at Method NY showed me this (he actually just did it and then had the unenviable task of explaining it to me once I took over the comp). Hopefully you understand it better than I did the first 30 minutes or so.
Cheers.


Nuke/Compositing: Inky Time Offset Effect from zeth willie on Vimeo.

Creating custom UV pass in MR and using it in Nuke

That's a mouthful.
On a job recently I got some secondhand Nuke goodness when a lighting TD showed me how they were using UV passes from Maya to "auto-track" some footage into their shots (I wasn't on that job). The basic issue was that a lot of footage had to go onto screens in the spot and some of that footage wasn't ready or the client was changing their mind about what the footage should be. So, in short, any manual trick to the get the footage locked onto the CG screens required redoing some additional work in post, in terms of tracking, etc. Additionally, sometimes late notes were coming in about animation changes to the screens themselves, which meant that there was no option to render "in-camera" in Maya, it had be done in post.
 So the simple solution was to render the screens with properly adjusted UV's as UV passes. This automatically locked the footage in place and wasn't dependent on any additional work once the comp was built, even if the footage had to be completely replaced or the animation of the screen itself changed. Pretty sweet. While I'm sure some people think this is obvious, I didn't (and neither did a lot of the other people I was working with. So I'm not the only ignorant one.)
In any event, I also realized that I never really followed up on any render pass stuff in Maya 2010/11, so the first vid below is basically what we're trying to do and how to get custom color passes out of Mental Ray (as opposed to the "regular" passes that are pre-set, like reflection, diffuse, etc). I use this method to get out RGB matte passes and a UV pass in EXR format.
The second video is how to actually use the UV pass in Nuke to get the basic effect we're looking for. Nothing crazy, just basic use of the UV pass.



Maya/Mental Ray: Custom Color Passes (2010) Part 1 - UV Pass from zeth willie on Vimeo.


Maya/Mental Ray: Custom Color Passes (2010) Part 2 - UV Pass from zeth willie on Vimeo.