How to Light Wrap [now @PVC]

This mini-roundup has been updated and moved to Pro Video Coalition, How to Light Wrap.

Reverse stabilization and 'Roto Assist'

Chris Zwar shared some resources on first stabilizing shots with camera movement, then doing keys or roto in a thread on the AE-List on the Roto Brush tool ("roto assist" when it bogs down) .

For more on the Roto Brush see AE Help (stabilization) and AEP posts with Roto Brush or stabilization resources. In addition to this advice, there's more from Chris on Thoughts on keying - The Myth of the Single-Click:

"Roto Brush will disappoint anyone who HASN'T had to do meticulous frame-by-frame rotoscope work before, and therefore doesn't know how tedious and difficult roto can be. Having a tool that gets you 70% of the way there is still a valuable time saver. But I haven't yet had a shot where it worked perfectly by itself. [snip]

In the same way that keying can be improved by pre-prossessing the footage to remove grain and adjust hue/saturation, images can also be pre-processed to improve rotoscoping too, and to help the roto brush plugin.

When I'm doing roto on any scene with camera movement I use a 3-step inverse camera process- firstly I motion stabilise the shot, then I work on the stabilised shot, then I put the original camera movement back in. I call it 'inverse camera' but it's also called 'reverse stabilisation' and it's demonstrated in a much more interesting way by Andrew Kramer:

http://www.videocopilot.net/tutorials/demon_face_warp/

It's also demonstrated on the Creative Cow:
http://library.creativecow.net/articles/oconnell_pete/roto.php

And the technique is then elaborated on by Roland:
http://library.creativecow.net/articles/kahlenberg_roland/reverse_stabilization.php

If I'm working with people who are new to rotoscoping then I get them to watch Andrew's tutorial first, because working on stabilised footage can make the roto process so much easier."

Rotoscoping Hair: basic options

Scott Squires has some tips on Rotoscoping Hair at a new Focal Press website, Postopolis. By the way, if you roto and key hair, sometimes it's faster to duplicate the keyed hair to make it more distinct rather than brutishly mess with controls.

So far there's no overall review of roto in CS5 (with significant additions of the Rotobrush and Mocha Shape), but Mark Christiansen's new AE book on VFX & CS5 is out on Monday. For now you can find more on the basics of rotoscoping in the roundup Rotoscoping tips and other AEP posts tagged roto, in Rotoscoping introduction and resources in AE Help, and at Scott's blog Effects Corner. See also Scott Stewart on cutting the perfect matte and Stu Mashwitz on the basic of procedural matte extraction, both from the out-of-print Masters of Visual Effects:

Masters of Visual Effects 2.6 - Rotoscoping from Matt Silverman on Vimeo.

Masters of Visual Effects 2.3 - Keying from Matt Silverman on Vimeo.

Greenscreen and keying resources

Chris and Trish Meyer posted Greenscreen Resources on PVC with info on some tips, tricks, and supplies.

There's a few more in this grab bag from previous AEP posts, some of which were also listed by Trish and Chris:

• Jonas Hummelstrand's Greenscreen and Bluescreen Checklist
• Alex Lindsay's Greenscreen Primers at PVC
• Chris Meyer's quick overview of Keylight on Adobe Video Workshop that gets right to the point.
• Chris Meyer posted An Illuminating Discussion: PVC writers weigh in on what they would recommend for a lighting kit.
• After Effects CS4 Help has nice succinct overview and tips, updated in CS5 as Keying introduction and resources and Compositing and transparency overview and resources.
• Mark Christiansen's chapter in AE Studio Techniques, which covers the Keylight filter in After Effects and much beyond. A small portion of his info was released in book teasers, Color Keying in After Effects CS3 and a video presentation of Keylight.
• Video training on Keylight and a greenscreen book from Toolfarm
• Toolfarm later added In Depth: Keying: Introduction & Frequently Asked Questions about Shooting Greenscreen and In Depth: Keying: Pre-Processing Greenscreen Footage for Keying
• Tutorials on 'super tight' garbage mattes in After Effects
• 9 Tools for live chroma keying, from Topher Welsh
• Amidst other advice Adam Wilt says use Chroma Smoothing in Final Cut, as quoted in an AEP post Jaggies on Chroma Key.
• A personal observation under a deadline -- duplicating a layer with a-bit-too-aggressive key on hair can help give the hair some extra blending detail.
• Fxguide's 'Art of' Keying (history and survey to 2005) & more
• Alex Lindsay's explanations of AE's Color Difference Keyer (a sample from the Composite Toolkit) will feed your head and help you understand some of what goes on behind the scenes in keying filters. The link is broken for now but you can see similar logic (with nodes instead of pre-comping isolated channels) in the Overview of the Color Difference Keyer in Conduit.
• from Masters of Visual Effects, a 30-minute video on keying and procedural mattes hosted by Stu Maschwitz
• Chris Zwar has "Thoughts on keying" in 3 parts - Technology, The Myth of the Single Click, and Compositing
• How to Light Wrap: Blending composite edges with and without 3rd party filters, an AEP roundup

Update:

Premium Beat introduced keying in Keying Fundamentals in Adobe After Effects. For more, see Todd Kopriva's outline of a set of four video tutorials on color keying by Andrew Devis.

Better Keying from Production to Post was a free class on green screen. Sponsored by Tiffen, the webinar featured Marco Paolini and Richard Harrington.

Jeff Foster, author of The Green Screen Handbook, was the host of a series on Splice Vine, August: Keying / Matting. See also FxGuide's Art of Keying and The Art of Roto, both by Mike Seymour, 'Super tight' garbage mattes in After Effects, and Rotoscoping tips on AEPortal archive. Here's Best Practices in Software Keying, from Jeff Foster's video2brain course Fundamentals of Compositing, Tracking, and Roto Techniques with After Effects: 

Ultra Key in Premiere CS5

At AdobeTV, Tracy Peterson shows how to create clean keys quickly using the Ultra Key chroma keyer in Adobe Premiere Pro. By now Keylight in After Effects is well known and high-quality, but the Ultra Keyer may come in handy sometime even if it's not GPU-accelerated and only supports 8-bits per channel.

Keying, Time Remapping, & Stills in Premiere CS5

The latest from Jason Levine is embedded below.

Note: the Time Warp effect from CS3 and CS4 was removed from Premiere CS5, but there's always Pixel Motion and Time Warp in After Effects if you need better results.


DSLR Workflow in Premiere Pro CS5 - Keying, Time Remapping & Stills from Jason Levine on Vimeo.

Update: Karl Soule added another on DSLR,

Fxguide's 'Art of' Tracking, Keying, Roto, Optical Flow, HDR, 3D Stereo, & more

Fxguide's 'Art of' series is still pretty good. Here's what's easily found in the series:

• The Art of Tracking
• The Art of Keying
• The Art of Roto
• The Art of Wire Removal
• The Art of Optical Flow
• The Art of HDR
• The Art of Digital 3D Stereoscopic Film
• Matte Painting: 1, 2, 3, 4

Covering some of the same ground is "classic" VFX training resurrected for now on Vimeo, the out-of-print Masters of Visual Effects.

Masters of Visual Effects resurrected

There's some classic VFX training from day of yore available on Vimeo, the out-of-print Masters of Visual Effects. The tapes covered Basic Compositing, Keying, Tracking, Paint, and Rotoscoping by some famous presenters. Here's roto:

Masters of Visual Effects 2.6 - Rotoscoping from Matt Silverman on Vimeo.

9 Tools for live chroma keying

Topher Welsh has a roundup of 9 Tools for On Set Live Chroma Keying at Pixel Art.

'Super tight' garbage mattes in After Effects

Topher Welsh has a quick tip on creating "super tight" garbage mattes to aid keying. He uses a basic After Effects color key like Color Range then applies the Simple Choker filter with a negative setting, expanding the matte to let an advanced keyer like Keylight to work more subtle magic. This technique that can also be found in Making It Look Great 5 with Maltaannon.

The technique is inspired in part by an older video by Aharon Rabinowitz, Super Tight Junk Mattes which used Auto-Trace and the Simple Choker to refine garbage mattes (project files are still available at Cow). Aharon similarly leverages convenient Red Giant filters in a more recent tutorial, RGTV Episode 4: Better Compositing Techniques.

Also there's no reason you can't use a copy of the matte with Simple Choker to do a choke for a hold out matte to preserve the keyed subject (as seen in Commotion Complete by Matt Silverman and recent keying training from Toolfarm). Here's Aharon's older tutorial and the new one by Topher:

How to Light Wrap [now @PVC]

This page has been updated and moved to Pro Video Coalition, How to Light Wrap.

Keying with Toolfarm

Professional Keying with Keylight is the latest video training from Toolfarm's Expert Series. It takes you through pulling tight and clean keys with Keylight in After Effects and shows you how to overcome problem areas like wispy hair and textures on edges. There's also tricks for making composites believable and a greenscreen shot and background plate, for $39. An excerpt reminds me of some of Matt Silverman's methods for developing mattes procedurally in the now defunct Commotion.

And available soon is Greenscreen Made Easy: Keying and Compositing Techniques by Jeremy Hanke and Michele Yamazaki. Harry Franks says, "If you are looking to get started with greenscreen production as a hobbyist or a professional, this book has everything you’ll need to hit the ground running. If you are a motion designer and visual effects artist with little exposure to the “other world” of production, including cameras and lighting, you’ll want to grab this book for a great primer on the subject." For flavor, see also an earlier article by earlier article Noise and Artifact Suppression Tips by Michele Yamazaki.

More on keying can be found in the recent AEP post Greenscreen Primers.

Greenscreen + Keying Primers

Alex Lindsay has his Greenscreen Primer at PVC, which begins to show you the benefit of using video scopes to get a good key and maximize dynamic range.

Other helpful resources include:

• Jonas Hummelstrand's Greenscreen and Bluescreen Checklist
• Mark Christiansen's chapter in AE Studio Techniques, which covers the Keylight filter in After Effects and much beyond. A small portion of his info was released in book teasers, Color Keying in After Effects CS3 and a video presentation of Keylight.
• Chris Meyer's quick overview of Keylight on Adobe Video Workshop that gets right to the point.
• After Effects Help has nice succinct overview and tips
• Amidst other advice Adam Wilt says use Chroma Smoothing in Final Cut, as quoted in an AEP post Jaggies on Chroma Key.
• Alex Lindsay's explanations of AE's Color Difference Keyer (a sample from the Composite Toolkit) will feed your head and help you understand some of what goes on behind the scenes in keying filters.

Purely personal observations include: 1) for some reason converting to uncompressed picture formats can help you better key some compressed formats, and 2) under a deadline duplicating a layer with a-bit-too-aggressive key on hair can help give the hair some extra blending detail.

Maltaannon's ceLightWrap

In a video tutorial Maltaannon shows you how to do a "light wrap," that is, "make your keyed out footage blend better with the background by casting light on it from surrounding elements." He's also selling a "Custom Effect" for this called ceLightWrap (CS3) for 9.95 EUR (~ $14).

You can find similar approaches to producing a lightwrap in the several AE books, in a few plug-ins (like one now by Red Giant), and around the web.

UPDATE: at some point custom effects stopped being supported. There's more on light wraps in How to Light Wrap: Blending composite edges with and without 3rd party filters, now at PVC.

How to Light Wrap

Blending composite edges with and without 3rd party filters

- See more at: http://www.provideocoalition.com/how-to-light-wrap#sthash.bhEjmKuo.dpuf

How to Light Wrap

Blending composite edges with and without 3rd party filters

- See more at: http://www.provideocoalition.com/how-to-light-wrap#sthash.bhEjmKuo.dpuf

The Colbert Report's 2nd greenscreen challenge

The Colbert Report is having another greenscreen challenge -- this time it's Project Make McCain Exciting: "when Republican Presidential nominee John McCain addressed a crowd in Kenner, Louisiana on June 3, he did so in front of a green screen, thereby issuing a bold challenge to Americans to make him seem more exciting."

Projects by Sam DeWitt and others played last night (see the Make McCain Exciting Challenge segment). There's plenty of room for more submissions, though George Lucas might not show up with the lightsaber for the show winners like last time.



Update: someone noted that another entry was by one John Knoll.

Jaggies on Chroma Key

Good basic advice from SF Cutters' Cutter-Talk:
>> I digitized the footage as DVCPRO50 widescreen, and it looks excellent, but when I go to chroma key it, I end up with stong jaggies on all moving edges.>>

If the "strong jaggies on moving edges" are simply the same sort of every-other-line jaggies you see on interlaced footage (jaggies move smoothly with the edge and are jagged in proportion to the amount of motion), don't worry about it (as long as the target output is interlaced).

If instead these are a sort of "fixed pattern steppy edge" where the edges of the key have discrete, coarse locations, with remain stationary as the edge moves within a 2-pixel radius, then it's a chroma subsampling issue, and you should try the following things:

1) Make sure you apply the "Chroma smoothing - 4:2:2" filter as the first effect on the source clip. If you're using FCP's standard keyers this makes a huge difference.

2) If interlaced, make sure you're viewing the rendered result on an interlaced CRT, not the Mac's screen, nor a flat panel with dodgy deinterlacing.

2a) You realize, I hope, that the FCP screen only ever gives you something even remotely close to a pixel-by-pixel-accurate view when the Canvas is at 100%?

3) Play with the edge parameters in whatever keyer you're using.

I've had excellent results (faster to set up and superior quality) using DV Garage's DV Matte Pro (no involvement with DV Garage except as an early beta tester and now as a paying customer).

Adam Wilt / shoots, edits / Mountain View, CA USA