dynafx
18-05-2005, 01:40 PM
Art of Roto (compositing)<br>
<br>
Matt Silverman of Phoenix Editorial provides a history of Roto and summary of Roto tools, terms and available programs.<br>
<br>
Rotoscoping is the process of manually altering film or video footage
one frame at a time. The frames can be painted on arbitrarily to create
custom animated effects like lightning or light-sabres, or traced to
create realistic traditional style animation or to produce hold-out
mattes for compositing elements in a scene.<br>
<br>
As a VFX artist, you are primarily creating motion graphics or visual
effects. Without a thorough knowledge of rotoscoping and how it fits
into the modern digital pipeline, you are limiting just how far you can
take an effect or design.<br>
<br>
The art of rotoscoping changed considerably with the introduction of
digital tools such as Commotion, Digital Fusion (DF), Shake, Combustion
(C3) and After Effects (AE). With a thorough knowledge of rotoscoping,
digital artists can create better live-action or CG composites as well
as amazing visual effects. Various rotoscoping techniques are covered
below, including matte creation, effects painting, paint touchup,
digital cloning, and motion tracking as well as a brief history of the
craft.<br>
<br>
<div align="left">
<p><b><font color="#990033">Historical overview of rotoscoping</font></b><br>
</p>
</div>
<p><font color="#990033"><br>
<b>Fleischer Studios</b><br><br>
</font>A
true pioneer of animation, Max Fleischer produced the Popeye and Betty
Boop animated series, as well as the animated features ?Gulliver?s
Travels? and "Mr. Bug Goes to Town." With his brother Dave, he founded
the Fleischer Studios in the early 1920?s, which offered a less
sentimental animated vision of the world than the rival Disney studio.
Perhaps most importantly, Fleischer invented the rotoscope, a device
that changed the look of animation forever.<br>
<br>
<img src="http://www.fxguide.com/modules/fxtips/files/art_of_roto/fleischerstudios.jpg" alt="" align="left" border="0" height="300" hspace="5" vspace="5" width="214" border="0">Born
in Vienna Austria in 1883, Max Fleischer immigrated with his family to
America at the age of four. His artistic skills were quickly
recognized, and instead of attending public high school he opted for
the Art Students League in New York. While attending school he landed
his first job at the Brooklyn Daily News, where he worked as an
assistant in the cartoon department. Within a few years, he was a
full-time staff artist with his own comic strip. He then moved on to
Popular Science Monthly, which sparked a life-long fascination with
machinery and inventions. While working at this magazine, Fleischer
began working on his plans to create the rotoscope.<br>
<br> Early
animated films were crude, jerky and difficult to look at. They were
not very popular and were only tolerated because they were a curiosity.
Max Fleischer aimed to change this by inventing a device that would
allow them to project live action film onto the glass of an animation
stand. The animators could then place paper on the animation stand and
trace the live action footage one frame at a time. This device, named a
Rotoscope, was patented by Max Fleischer in 1917.<br>
<br>
In a 1920 New York Times interview, Fleischer said, "An artist, for
example, will simply sit down and, with a certain character in mind,
draw the figures that are to make it animated. If he wants an arm to
move, he will draw the figure several times with the arm in the
positions necessary to give it motion on the screen. The probability is
that the resulting movement will be mechanical, unnatural, because the
whole position of his figure's body would not correspond to that which
a human body would take in the same motion. With only the aid of his
imagination, an artist cannot, as a rule, get the perspective and
related motions of reality."<br>
<br>
The rotoscope, though, allowed animators to work from a filmed image,
which gave them the guidance they needed to create more graceful and
realistic movement on screen. "It was beautiful to watch, rather than
very annoying to watch," Fleischer said.<br>
<br>
<img src="http://www.fxguide.com/modules/fxtips/files/art_of_roto/Koko-ball-3.jpg" alt="" align="right" border="0" height="199" hspace="5" vspace="5" width="200" border="0">The
first cartoons created by the Fleischers using the Rotoscope were the
Koko the Clown series, and then went on to utilize it in Betty Boop and
Popeye. Though they used rotoscoping to create the main characters,
they continued to rely on traditional rubber hose style animation in
their cartoons. The Fleischers pioneered other traditional animation
priniciples in their studio which changed the face of modern animation,
right up to today. Most animators at the time would use the technique
of ?Straight Ahead Action?. Animators would simply start drawing their
sequences at the beginning and straight ahead to the end. The
Fleischers used another technique called ?Pose to Pose? animation, in
which the animators would produce main extreme poses, or keyframes,
then fill in the in-betweens. The difference was that the Fleischers
would have assistants draw the in-betweens while the lead animators
moved on to create more keyframes. Though at the time this eventually
led to labor problems and striking workers at Fleischer Studios, the
practice is still used today by traditional cel animation companies,
and has been translated into the automatic ?tweening? processes found
in computer based animation tools.<br>
<br>
<font color="#990033"><b>Disney</b><br><br>
</font>During
the 1930s, the Fleischers found themselves in an on-going competition
with another animator -- Walt Disney. The Fleischers and Disney
constantly raced one another to each new milestone in animation --
first sound cartoon, first color cartoon, and first feature. But
according to Max Fleischer?s son, Richard Fleischer, Max and Dave often
came in second, largely because the studio behind them, Paramount,
didn't offer the support they needed.<br>
<br> Walt Disney also
turned to rotoscoping, for ?Snow White?. At the time, Fleischer
considered suing Disney for patent violation, but in doing preliminary
research, his attorneys discovered that before Fleischer's patent, a
company in Wilkes-Barre, Pa., had created a device similar to the
rotoscope. The company, Bosworth, Defresnes and Felton, had never
patented it, so Fleischer actually was entitled to sue, but he
evidently lost interest in pursuing the Disney case after hearing about
the earlier machine.<br>
<br>
The movements of Snow White herself were acted out by a high school
student named Marjorie Belcher, later known as dancer Marge Champion.
Initially, Disney intended to use Belcher's movements as a guide for
the dancing in the cartoon, but soon he opted to use it more
extensively. This was partly because the animators otherwise used
themselves and their own facial expressions as the basis for their
characters' faces, Disney explained. "The artists looking at themselves
in a mirror sometimes were not so successful, because they were bad
actors and would do things in a stiff way," he wrote.<br>
<br>
Nevertheless, some of the Disney animators looked down on the idea of
rotoscoping. One of them, Don Graham, derided the technique as a
"crutch" for artists who lacked the skill to do their work on their
own. Another, Grim Natwick, said that even when the artists used the
device, they used it only as the basis for their work, adding heavy
elaboration and even changing the proportions of the original filmed
figures. "We went beyond rotoscope," he said.<br>
<br>
But rival animator Walter Lantz criticized the look of the rotoscoped
work in "Snow White." In press materials for his own project, "Aladdin
and the Wonderful Lamp," Lantz declared he would use the rotoscope only
for timing because of what he saw as its limitations, especially in
Disney's film. "This literal system resulted in two faults -- a
jittering movement that contrasted with the fluidity of the animals,
and the fact that the human characters were too accurate to be seen
beside the caricatures," he said.<br>
<br>
Yet rotoscoping did help the artists on "Snow White" maintain a
consistency that might otherwise have been impossible. On earlier
animated shorts, each character was done by a single animator; as a
result, the characters had a unity of style. Because "Snow White" was
so extensive, however, more than one artist had to work on each
character. Working from live-action footage offered them the best way
to create a cohesive look.<br>
<br>
<font color="#990033"><b>Analog Rotoscoping for Visual Effects</b><br><br>
</font><img src="http://www.fxguide.com/modules/fxtips/files/art_of_roto/birds.jpg" alt="" align="left" border="0" height="210" hspace="5" vspace="5" width="275" border="0">While
the technique is useful for animation, rotoscoping eventually became an
important tool for visual effects in general. From the 1940s through
the 1960s, U.B. Iwerks, a well-known animator, turned to effects work,
where he pioneered the use of the rotoscope on films such as Alfred
Hitchcock's ?The Birds? (1963).<br>
<br> Rotoscoping in visual
effects was used primarily to make holdout mattes. "You frequently want
to composite different elements into the same shot to create that
shot," explained Tom Bertino, who was head of Industrial Light &
Magic?s rotoscoping department from 1987-93. "By using the tracing to
create black mattes, you can hold out certain elements."<br>
<br>
For example, Bertino imagines a scene of an explosion behind two people
on-screen, where the explosion is added after the fact. "You could
print the explosion over the frame. But you'd also cover up the
people," he said. "You'd need to isolate them with the rotoscope." To
make a traditional holdout matte, a rotoscope artist would trace the
figures that had to be isolated onto an animation cel. The outline
traced onto the cel then would be filled in with black paint, so that
it would block the appropriate section of the frame. "You create a
solid black matte," Bertino said. This black matte then could "hold
out" the part of the explosion image where the two people would appear,
so that when the two images were printed together, the people would
appear to be in front of the explosion.<br>
<br>
<img src="http://www.fxguide.com/modules/fxtips/files/art_of_roto/bertinoatwork.jpg" alt="" align="right" border="0" height="200" hspace="5" vspace="5" width="265" border="0">
Rotoscoping also could be used to stabilize a shaky film image. To do
stabilization, each film frame was rotoscoped onto an alignment chart.
A comparison of the charts allowed changes in position to be tracked
from frame to frame. Using this information, an optical copy of the
film could be made, with the printer offsetting the shifts in each
frame's movement.<br>
<br> Bertino said people underestimate the
difficulty of rotoscoping during the photochemical era: "It was a
painstaking process. There were so many moving parts to the rotoscope
camera, and so many places for things to get out of hand." Rather than
being a refuge for the unskilled artist, he added, rotoscoping was a
demanding craft. "The rotoscoper had to be a skilled animator to make
the line follow through. That's actually something that plagued some
early uses of the rotoscope as a special effects tool -- without actual
animators to handle it, it could get jittery."<br>
<br>
Good rotoscope artists were very precise about their work. "It was so
exacting," Bertino said. "It's almost like -- I don't know if you?ve
ever seen those incredibly detailed Chinese tapestries that they made
in the monasteries generations ago. They finally stopped making them
because the artisans would go blind. I'm surprised that more
rotoscopers didn't go that route."<br>
<br>
Jack Mongovan, a paint and rotoscope supervisor at ILM, began his
career in traditional rotoscoping and has been working in the field for
19 years. He remembers working in rooms that were completely dark
except for the light coming out of the projector. The rotoscope artists
were at the mercy of the painters who would later fill in their
outlines, and who could with a few stray brushstrokes outside the
outline make the image suddenly jittery. "I would never go back to
traditional for anything," Mongovan said.<br>
<br>
<font color="#990033"><b>Digital rotoscoping for Visual Effects</b><br><br></font>
Today, rotoscoping is done in the computer, using programs such as
Shake, FFI and Pinnacle Commotion. The shift to computer-based
rotoscoping began in the early 1990s with a software called Colorburst,
an image editing tool like Photoshop, that later evolved into Matador.
"When computers became prodigiously viable around here, right after the
'Terminator 2'/'Jurassic Park' era, we realized that the computer had
great capabilities for this," Bertino said. "It obviously became much
simpler."<br>
</p>
<div align="center">
</div>
<p><br>
Mongovan said that today, one rotoscope artist can do the same amount
of work that eight used to do, and in one quarter of the time. This is
often because in traditional rotoscoping, each frame had to be drawn
individually. The computer, on the other hand, can use the previous
frame as a basis, which means most of the drawing may already be done.<br>
<br>
Rotoscoping software works using splines, which are a series of points
connected by a line or curve. These splines are adjusted from frame to
frame, so that they continue to conform to whatever shape the artist is
tracing. Because rotoscoping software includes the tools to paint an
image, rotoscope artists now find themselves doing a lot of paint work
as well. "Rotoscoping is becoming the lesser part of what we do,"
Mongovan said. "We do so much more painting." Painting might mean
taking someone out of a shot, or replacing a sky, or painting out the
tennis balls used as visual effects tracking markers.<br>
<br>
Some skills remain necessary, including a sense of what is important.
"One of the hardest things for people to do in our department is to
realize that they're looking at a very zoomed-up plate," Mongovan said.
Also, he pointed out, a movie audience will see an image for only
1/24th of a second, too short a time to register flaws that may torture
the artists. More important is consistency. "I tell people, 'You can
paint that first frame wrong, just keep it wrong it all the way
through.'"<br>
</p>
<div align="center">
<p><img src="http://www.fxguide.com/modules/fxtips/files/art_of_roto/rotomk.jpg" alt="" border="0" height="242" width="350" border="0"><br>
</p>
</div>
<p>That
kind of understanding is key, Bertino agreed. "The secret to good
rotoscoping has always been -- regardless of what it's used for -- an
educated eye and good judgment as to what to include and what to leave
out," he said. "Most people think the rotoscope is very literal -- you
trace what's there, and that's it. It's possible to put too much detail
and confuse matters. You need to have that sense for judicious editing.
That hasn't changed at all. And not everybody's got that."<br>
<br>
<font color="#990033"><br>
</font></p>
<div align="left">
<p><font color="#990033"><b>Summary of Roto Tools</b><br>
</font></p>
</div>
<p><br>
<font color="#660000">
<b><a href="http://www.adobe.com/products/aftereffects/main.html" target="_blank" target="_blank">After Effects</a></b></font><br><br>
After Effects was the first tool to bring professional compositing
motion graphics and effects functionality to the desktop. After Effects
was originally developed by CoSA, then aquired by Aldus, which in turn
was aquired by Adobe. After Effects had very limited rotoscoping tools
in earlier versions, with only one rotospline and no paint tools, but
this is slowly changing. Version 4 added multiple rotosplines for
cutting mattes, version 5 added vector paint, and version 6.5 has added
cloning tools and tracker advancements (we still haven't tested these
improvements). It is still lacking b-splines as well as the realtime
roto performance found in more advanced roto tools like Commotion. Tip:
<a href="http://www.redgiantsoftware.com/commotionrotoimport.html" target="_blank" target="_blank">Red Giant software</a> offers a Commotion to AE roto import plugin<br>
<br>
<br>
<br>
<br>
<b><a href="http://www.discreet.com/products" target="_blank" target="_blank">Flint/Flame/Inferno/Fire/Smoke</a></b><br><br>
<img src="http://www.fxguide.com/modules/fxtips/files/art_of_roto/flame.jpg" alt="" align="left" border="0" height="221" hspace="5" vspace="5" width="394" border="0">Discreet?s
Advanced System, which include Flint, Flame, Inferno, Fire, and Smoke,
run on SGI workstations and range in price from $60,000 to over
$500,000. These products offer a complete post-production solution,
including very powerful and fast rotoscoping tools. The painting and
cloning tools are top notch, with excellent brushes and advanced
features including brushed based warping. The rotosplining
functionality is excellent, though not quite up to par with Commotion
due to a lack of b-splines and the inability to play spline over a
moving image in realtime. Tracking is very fast and very accurate. Many
facilities using Discreet?s advanced systems offset roto work to Macs
and PCs running Commotion, Shake or Combustion.<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
</p>
<p><br>
</p>
<p><b><a href="http://www4.discreet.com/combustion/" target="_blank" target="_blank">Combustion</a></b><br><br>
<img src="http://www.fxguide.com/modules/fxtips/files/art_of_roto/combustion.jpg" alt="" align="right" border="0" height="217" width="350" border="0">In
1997, Discreet aquired Paint and Effect from Denim Software. Paint
offered a vector based painting and cloning system for Mac and PC,
while Effect offered compositing capabilities. Discreet re-designed the
interfaces to make the applications more Discreet like, and merged the
two applications into Combustion. Along the way, they also replaced
some of the core functionality like Keying, Color Correction, and
Tracking with the same tool set found in Discreet?s Advanced Systems.
Combustion 2.0 added additional Advanced Systems features, including
the same rotosplines found in Flame. Combustion 3.0 took the product
even further with an edit operator, flash output and much more, most
significantly a flow diagram UI feature that many users feel more
comfortable working with. Combustion roto spline files can be opened
directly in the larger Inferno/flame/flint products.<br>
<br>
</p>
<p><br>
<br>
<br>
<br>
<br>
<br>
</p>
<p><br>
</p>
<p><b><a href="http://www.curious-software.com/products/gFx/" target="_blank" target="_blank">Curious gFx Pro</a></b><br><br>
<img src="http://www.fxguide.com/modules/fxtips/files/art_of_roto/gfx.jpg" alt="" align="left" border="0" height="211" width="350" border="0">gFx
is a relatively new product for the Mac OSX. Unlike other paint
programs it is designed around a stong user interface that fully
embraces moving footage, as such it can import, composite, track, or
stablise footage easily. The spline shapes can not yet be exported and
the product does not fully import Photoshop files and maintain their
structure, but this is planned for an upcoming release. the product
does have specialist wire removal tools and a very friendly and
interactive user interface. One of Curious's founders is the man behind
Parrallax, and it shows in some of the depth of tools already
available, 16bit raster paint with an excellent brush engine, and
b-spline rotosplines with an excellent transform points UI, motion blur
on splines, grouping splines, selective edge feathering (ie. advanced
gradient), and more.</p>
<p><br>
<br>
<br>
</p>
<p><br>
<br>
<br>
<br>
<br>
</p>
<p><b><a href="http://www.eyeonline.com/" target="_blank" target="_blank">Digital Fusion</a></b><br><br>
<img src="http://www.fxguide.com/modules/fxtips/files/art_of_roto/df_fullscreen.jpg" alt="" align="right" border="0" height="283" width="350" border="0">Digital
Fusion started in Sydney and moved to Toronto, Canada. At one stage a
version of Fusion was provided with Alias 3D - but today Eyeone has
gained one of the strongest postions in NT/Windows desktop compositing
solutions. Eyeon has two main products Digital Fusion and DFX +.<br>
Digital Fusion 4 is eyeon?s flagship product and marks the ninth major
release of this powerful compositor. DFX+ 4 is the 8-bit expandable
version of eyeon?s image processing software, Digital Fusion. DFX+ is
based on the architecture of DF4 and offers a number of significant
enhancements to its predecessor, DFX, including the flexible flow,
superior character generation, PSD import into separate layers for
animation, and more.<br>
Since Shake's move away from NT/Windows DF has provided a powerful cost effective solution.</p>
<p>
</p>
<p><br>
<br>
<br>
</p>
<p><br>
<br>
</p>
<p><b><a href="http://www.apple.com/shake" target="_blank" target="_blank">Shake</a></b><br>
<img src="http://www.fxguide.com/modules/fxtips/files/art_of_roto/shake2.jpg" alt="" align="left" border="0" height="270" width="350" border="0">Shake
has 3 options for Roto, Quickpaint, Quickshape, and Rotoshape.
Quickpaint is a procedural paint package inside Shake. You can paint
frame by frame and then view in realtime or paint with interpolation.
As all the paint elements can be animated over time it is a reasonable
roto tool. Quickshape is a basic roto tool, somewhat now completely
over shadowed by Rotoshape. Rotoshape allows variable edge softness and
logical operations between roto shapes. The rotos in Rotoshapes are
classic spline shapes with complex parent child relationships - and
velocity based motion blur. For complex rotoscoping this gives very
accurate results. Both Rotoshape and quickpaint can use shakes 2D
trackers. It is worth noting that given Shake is a node workflow model
it is possible to paint or roto through a track or image transform.<br>
</p>
<p><br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
</p>
<p><b><a href="http://www.adobe.com/products/photoshop/" target="_blank" target="_blank">Photoshop</a></b><br><br>
<img src="http://www.fxguide.com/modules/fxtips/files/art_of_roto/photoshop.jpg" alt="" align="right" border="0" height="196" width="350" border="0">The
most ubiquitous graphics application in the world was probably the
first digital rotoscoping tool to be used in film and video post
production. Though Photoshop was initially intended for still images,
it can work with motion by importing frames one at a time or importing
filmstrip files from video applications. Photoshop?s brush engine is
the benchmark everyone else strives for, and gives excellent control
when using pressure sensitive Wacom tablets. The biggest drawback is a
lack of a realtime preview of sequential frames. You will not know how
well your cloning is working out until you play back your clip in
realtime at full resolution. After painting numerous frames in
Photoshop, the sequence must be brought back into an editing or
compositing application such as Final Cut Pro to see realtime playback.
This is a painfully slow way of working. And since it isn?t intended
for video, it lacks travelling matte capabilities and motion tracking.<br>
</p>
<p>Other older products:</p>
<p><b><a href="http://www.pinnaclesys.com/ProductPage_n.asp?Product_ID=110&Langue_ID=7" target="_blank" target="_blank">Commotion</a></b><br>
<br>
Developed by Industrial Light and Magic Visual Effects Superviser Scott
Squires, Commotion was used for years at ILM before Scott formed Puffin
Designs and released it to the public. Commotion, then called Flipbook,
was often sighted at ILM and mistakenly referred to as the ?secret ILM
motion version of Photoshop?. Though Commotion looked very similar to
Photoshop in some respects, Commotion?s interface and tools were
designed for moving images, and was the first tool on the desktop to
offer realtime ram based playback. This realtime core functionality was
the foundation for all of the roto tools added as the product
developed. Advanced roto tools include raster based paint, spatial and
temporal cloning, wire removal tools, auto-paint, unlimited bezier and
natural cubic b-splines, motion blur on rotosplines, and a very fast
and accurate motion tracker. Commotion quickly became the de-facto roto
tool in the industry, replacing Matador in most post facilities. Puffin
Designs was aquired by Pinnacle Systems in 2000, but sadly development
has stopped on the product, most if not all the original developers has
long since left and no new work has really been done on the product in
the last 3 years. Importantly Commotion curves can be exported and
imported into AfterEffects, see AE above.<br>
<br>
</p>
<p><b><a href="http://www.softimage.com/Products/Other/Matador/Product_Info/matador/index.htm" target="_blank" target="_blank">Matador</a></b><br><br>
Matador was originally developed by Brittish developer Parralax, and
acquired by Avid along with Parralax? compositing application Illusion.
Available only on the SGI platform and priced around $15,000, Matador
was one of the first digital rotoscoping tools which gained a wide
acceptance in the film post production pipeline. Matador started as a
tool made for editing still images, so many of the tools used for
motion work were not well thought out. Matador provides excellent matte
creation tools including b-splines, motion tracking, and a full set of
painting and cloning tools, with full 16bit/channel support. Avid
stopped development of Matador in the late 90?s. The original
developers tried to spin it off into a new company called ?Blue?, but
that never took off.<br>
There are new Roto tools that have now been incorporated into Softimage
XSI compositor in V.4, but these are not Matador - as many people
believe.<br>
</p>
<p><b><a href="http://www.newtek.com/" target="_blank" target="_blank">Aura</a></b><br>
<br>
Newtek is mostly known for their 3D application Lightwave. Aura was a
stand-alone paint application designed for film and video. It hasn?t
become widely accepted in the industry, and mostly used by Lightwave
users to finesse 3D renders. Some advanced features include a
16bit/channel paint engine, and auto-paint. Newtek has now stopped
supporting the program and as of June 2003 with Lightwave 3D 7.5 -
Newtek offers DFX+ at no additional cost.<br>
<br>
<b><a href="http://www.media100.com/" target="_blank" target="_blank">Roto DV</a></b><br>
<br>
Originally developed as a product named ?Roto? by a failed start-up
company called Post Digital, Roto DV was aquired by Radius, which later
turned it?s name into Digital Origin, and then was aquired by Media100.
Though it was called Roto, it actually didn?t have very sophisticated
roto tools, and the ones that were actually pretty cool never made it
into the shipping product. Media100 has no information on their website
about this product, so we assume it is no longer developed or supported.<br>
</p>
<div align="left">
<p><br>
<font color="#990033"><b>Rotoscoping in the modern post-production pipeline.<br>
</b></font></p>
</div>
<p><br>
<font color="#660000"><b>Effects Painting<br><br>
</b></font>Effects
Painting is generally used to quickly add new elements to a scene.
Instead of creating elaborate particle effects in 3D simulation
software like Maya, many effects can be done faster by a skilled artist
using a paintbrush or airbrush in a paint application. Effects like
lightning or light-sabres can be painted one frame at a time. More
advanced roto tools offer auto-paint capabilities which allow you to
record brush strokes and then play them back over a selected range of
frames. Some roto applications also allow you to add jitter to the
brushes, as well as add the ability to paint the stroke out over time.<br>
<br>
There are two types of paint engines used in modern graphics
applications; Bitmap (also known as raster) and Vector. Raster paint
engines are destructive in the sense that they replace the pixels being
painted onto with the color from the paint stroke. Photoshop,
Commotion, and Flame are raster based applications. This is a very fast
way of working since the frame is immediately updated and the results
can be played back in real time without rendering. Vector based paint
engines, like Illustrator, Shake, After Effects Vector Paint, or
Combustion, use points and splines to define a brush stroke, and do not
destroy the underlying pixels. This non-destructive process allows you
to edit paint strokes at any time, though you pay the price in speed
since the strokes need to be rendered before they can be previewed in
realtime. The other disadvantage is that hundreds of channels will be
created with the spline information even if you do not plan on using
them.<br>
<br>
<font color="#660000"><b>Cloning/Paint Touch-Up<br><br>
</b></font>Most
paint work done in the rotoscoping process is used for touching up film
or video footage. This includes removing wires and rigs, removing
logos, dust busting, scratch removal, etc. In these circumstances, the
roto tool must be able to provide temporal and spatial cloning. Spatial
cloning is a type of cloning which takes pixels from one position of
the frame, and paints the source onto another position on the frame.
Photoshop?s rubber stamp tool is an example of spatial cloning.
Temporal cloning allows you to paint pixels from one frame in a
sequence to another frame. Commotion?s Super Clone tool is an example
of temporal cloning. A good roto tool should provide both of these
options together so users can offset position and frame number
together. Other cloning tools include wire removal tools which allow
you to draw a line to zip out a wire. Typically, wire removal tools
clone pixels from a specified value on either side of the line, then
smear the outside pixels together to cover up the wire or scratch. More
advance wire removal tools will add advanced cloning techniques to the
wire removal process. For example, Commotion looks at a specified
number of pixels on either side of the line, flips those pixel values
then cross dissolves to cover up the wire.<br> There are excellent
specialist plugin tools for wire removal such as Tinder's Furnace
plugins for Shake and discreet's inferno or flame<br>
<br>
<b><font color="#660000">Matte creation (Keying, Rotosplining, Painting)<br><br>
</font></b>Creating
hold-out mattes, sometimes referred to as masks or alpha channels, is a
major piece of the compositing process. A matte is a grayscale clip
which is used to stencil portions of the background footage. Anything
in the black area will be obscured, and anything in the white area will
show through (in some systems like Avid this is backwards). Any gray
area in the matte will be semi-transparent. Roto artists are expected
to cut precise mattes with consistent edges which will not chatter. If
the matte is sloppy, the shot will look fake. The best compositor will
produce unacceptable work if provided with poor mattes. Mattes can be
created with three different techniques; Extraction, Rotosplining, and
Painting. For most situations a combination of these three techniques
will have to be used.<br>
<br> Extraction is the process of
procedurally generating a black and white matte. This can be done by
shooting an element against a blue or green screen, then using a color
keyer to knock out the specified color. Sometimes bluescreens are not
practical, and in these cases other types of extractions need to be
performed. Luminance keying can extract a matte based on the luminance
values of the source. Either dark or light areas can be extracted into
a matte. An image can be de-saturated then leveled to create a high
contrast matte. Sometimes it is better to start with one of the color
channels to create an extraction. It is always a good idea to check out
each color channel to see how the contrast looks, then pick the best
one to start leveling into a high contrast matte. The Shift Channels
filter in AE or Commotion can shift one of these color channels into
the Alpha Channel, which can then be leveled into the final matte.
Another type of extraction is Difference Keying, which generates a
matte based on differences between two clips.<br>
<br>
Rotosplining is the process of creating vector shapes to manually cut
an element out of it?s background. These shapes can be re-positioned on
various keyframes, and the software will interpolate the in-betweens.
The process isn?t as automatic as an Extraction, but at least the
computer can interpolate some of the frames for you. Good roto tools
will offer multiple rotosplines with the ability to keyframe each shape
separately. By using multiple splines, complex elements can be cut out
from their background. For example, an actor running would have
separate shapes for the hand, forearm, upper arm, chest, torso, thigh,
shin, etc. By breaking the shapes down into smaller elements, it is
much faster to set the keyframes by moving the shape and not individual
points, and the software will interpolate much more accurately.
Commotion has the most advanced rotosplining tools on the market. Most
applications use bezier splines for their rotosplines, which require
tweaking both the points and the handles. Commotion has bezier splines,
but the real power is in the B-Splines, which are much easier to
control. B-Spline, also called Natural Splines, do not have the handles
found on Beziers. Instead they always create a curved surface depending
on how far apart the points are. The points default to an average
tolerance, and can be interactively changed to loosen or tighten the
curve. B-Splines are consistently faster and easier to work with than
beziers. Commotion also has the ability to play multiple shapes in
realtime over the background footage. This allows you to quickly
preview how your shapes are animating compared to the source footage.
Other important functions found in Commotion?s rotosplining tools
include directional feathering, unlimited splines, color coding and
naming splines, motion blurred mattes based on direction and velocity
of the splines, a curve editor for fine tuning the motion between
keyframes, rotating and scaling splines and selected points, global
position offsets, and composite previews.<br>
<br>
Mattes can also be generated with paint tools. This is generally the
last resort, as painting mattes generally will produce inconsistent
results due to the fact that every frame needs to be painted on.
Auto-paint functionality can help with this consistency problem, but
for the most part painting mattes should be left for final tweaking of
an extracted or rotosplined matte. Advanced rotoscoping tools offer the
ability to paint mattes directly into the Alpha Channel while
continuing to see an overlay of your RGB channel. This is sometimes
referred to as a Mask Overlay, or QuickMask, and is crucial for
painting complex mattes.<br>
<br>
<b><font color="#660000">Motion Tracking<br>
</font></b>Motion
Tracking is a computer based process which analyzes a pixel or
sub-pixel in a clip, and follows that pixel or sub-pixel to find the
exact coordinates on each frame. There are two primary uses for motion
tracking. The first is for stabilization, and the second is for match
moving.<br>
<br> Once a motion tracker knows where a sub-pixel is
on every frame, it can re-position the image on every frame in the
opposite direction to counteract a camera shake. This stabilization
process works fantastic in most cases. Tracking one point allows you to
stabilize position. Adding a second tracker will allow the software to
compare the relative positions of the two trackers, which can also
stabilize rotation and/or scale.<br>
</p>
<div align="center">
<p><img src="http://www.fxguide.com/modules/fxtips/files/art_of_roto/df_tracker.jpg" alt="" border="0" height="222" width="350" border="0"></p>
</div>
<p><br>
The second use for motion tracking is match moving. If you needed to
add a logo to a car door, you can track the handle on the door, then
apply that data to a logo on another layer. As mentioned above, a
second tracker can be added to match move a logo which needs to rotate
and/or scale. If perspective changes, four point tracking can be used
to track four points. Each tracker can then be assigned to a corner of
a CornerPin filter applied to the image.<br>
<br>
Serious roto tools need motion tracking to help automate tedious
processes, as well as to produce convincing results. Motion trackers
should allow you to track 1, 2, and 4 points simultaneously. Advanced
trackers, like the one found in Commotion, allow for unlimited point
tracking, and access to the tracked data in text format so it can
easily be used in other applications (Commotion can export text, as
well as data formatted for AE, Flame, Digital Fusion, Electric Image,
and other apps). Motion trackers should also allow you to apply the
tracking data to rotosplines and individual points on a rotospline for
automated matte creation, as well as attaching tracker data to paint
and cloning tools. And most importantly, the motion tracker has to be
accurate. Flame, Shake, Digital Fusion and Commotion have the fastest,
most accurate trackers.<br>
</p>
<div align="center">
<p><img src="http://www.fxguide.com/modules/fxtips/files/art_of_roto/boujoubullet.jpg" alt="" border="0" height="286" width="350" border="0"></p>
</div>
There
are excellent program for 3 dimensional camera tracking but these are
rarely used for roto, however programs such as boujou and boujou bullet
will import b/w rotos to aid in tracking<br>
<br>
Matt Silverman of Phoenix Editorial provides a history of Roto and summary of Roto tools, terms and available programs.<br>
<br>
Rotoscoping is the process of manually altering film or video footage
one frame at a time. The frames can be painted on arbitrarily to create
custom animated effects like lightning or light-sabres, or traced to
create realistic traditional style animation or to produce hold-out
mattes for compositing elements in a scene.<br>
<br>
As a VFX artist, you are primarily creating motion graphics or visual
effects. Without a thorough knowledge of rotoscoping and how it fits
into the modern digital pipeline, you are limiting just how far you can
take an effect or design.<br>
<br>
The art of rotoscoping changed considerably with the introduction of
digital tools such as Commotion, Digital Fusion (DF), Shake, Combustion
(C3) and After Effects (AE). With a thorough knowledge of rotoscoping,
digital artists can create better live-action or CG composites as well
as amazing visual effects. Various rotoscoping techniques are covered
below, including matte creation, effects painting, paint touchup,
digital cloning, and motion tracking as well as a brief history of the
craft.<br>
<br>
<div align="left">
<p><b><font color="#990033">Historical overview of rotoscoping</font></b><br>
</p>
</div>
<p><font color="#990033"><br>
<b>Fleischer Studios</b><br><br>
</font>A
true pioneer of animation, Max Fleischer produced the Popeye and Betty
Boop animated series, as well as the animated features ?Gulliver?s
Travels? and "Mr. Bug Goes to Town." With his brother Dave, he founded
the Fleischer Studios in the early 1920?s, which offered a less
sentimental animated vision of the world than the rival Disney studio.
Perhaps most importantly, Fleischer invented the rotoscope, a device
that changed the look of animation forever.<br>
<br>
<img src="http://www.fxguide.com/modules/fxtips/files/art_of_roto/fleischerstudios.jpg" alt="" align="left" border="0" height="300" hspace="5" vspace="5" width="214" border="0">Born
in Vienna Austria in 1883, Max Fleischer immigrated with his family to
America at the age of four. His artistic skills were quickly
recognized, and instead of attending public high school he opted for
the Art Students League in New York. While attending school he landed
his first job at the Brooklyn Daily News, where he worked as an
assistant in the cartoon department. Within a few years, he was a
full-time staff artist with his own comic strip. He then moved on to
Popular Science Monthly, which sparked a life-long fascination with
machinery and inventions. While working at this magazine, Fleischer
began working on his plans to create the rotoscope.<br>
<br> Early
animated films were crude, jerky and difficult to look at. They were
not very popular and were only tolerated because they were a curiosity.
Max Fleischer aimed to change this by inventing a device that would
allow them to project live action film onto the glass of an animation
stand. The animators could then place paper on the animation stand and
trace the live action footage one frame at a time. This device, named a
Rotoscope, was patented by Max Fleischer in 1917.<br>
<br>
In a 1920 New York Times interview, Fleischer said, "An artist, for
example, will simply sit down and, with a certain character in mind,
draw the figures that are to make it animated. If he wants an arm to
move, he will draw the figure several times with the arm in the
positions necessary to give it motion on the screen. The probability is
that the resulting movement will be mechanical, unnatural, because the
whole position of his figure's body would not correspond to that which
a human body would take in the same motion. With only the aid of his
imagination, an artist cannot, as a rule, get the perspective and
related motions of reality."<br>
<br>
The rotoscope, though, allowed animators to work from a filmed image,
which gave them the guidance they needed to create more graceful and
realistic movement on screen. "It was beautiful to watch, rather than
very annoying to watch," Fleischer said.<br>
<br>
<img src="http://www.fxguide.com/modules/fxtips/files/art_of_roto/Koko-ball-3.jpg" alt="" align="right" border="0" height="199" hspace="5" vspace="5" width="200" border="0">The
first cartoons created by the Fleischers using the Rotoscope were the
Koko the Clown series, and then went on to utilize it in Betty Boop and
Popeye. Though they used rotoscoping to create the main characters,
they continued to rely on traditional rubber hose style animation in
their cartoons. The Fleischers pioneered other traditional animation
priniciples in their studio which changed the face of modern animation,
right up to today. Most animators at the time would use the technique
of ?Straight Ahead Action?. Animators would simply start drawing their
sequences at the beginning and straight ahead to the end. The
Fleischers used another technique called ?Pose to Pose? animation, in
which the animators would produce main extreme poses, or keyframes,
then fill in the in-betweens. The difference was that the Fleischers
would have assistants draw the in-betweens while the lead animators
moved on to create more keyframes. Though at the time this eventually
led to labor problems and striking workers at Fleischer Studios, the
practice is still used today by traditional cel animation companies,
and has been translated into the automatic ?tweening? processes found
in computer based animation tools.<br>
<br>
<font color="#990033"><b>Disney</b><br><br>
</font>During
the 1930s, the Fleischers found themselves in an on-going competition
with another animator -- Walt Disney. The Fleischers and Disney
constantly raced one another to each new milestone in animation --
first sound cartoon, first color cartoon, and first feature. But
according to Max Fleischer?s son, Richard Fleischer, Max and Dave often
came in second, largely because the studio behind them, Paramount,
didn't offer the support they needed.<br>
<br> Walt Disney also
turned to rotoscoping, for ?Snow White?. At the time, Fleischer
considered suing Disney for patent violation, but in doing preliminary
research, his attorneys discovered that before Fleischer's patent, a
company in Wilkes-Barre, Pa., had created a device similar to the
rotoscope. The company, Bosworth, Defresnes and Felton, had never
patented it, so Fleischer actually was entitled to sue, but he
evidently lost interest in pursuing the Disney case after hearing about
the earlier machine.<br>
<br>
The movements of Snow White herself were acted out by a high school
student named Marjorie Belcher, later known as dancer Marge Champion.
Initially, Disney intended to use Belcher's movements as a guide for
the dancing in the cartoon, but soon he opted to use it more
extensively. This was partly because the animators otherwise used
themselves and their own facial expressions as the basis for their
characters' faces, Disney explained. "The artists looking at themselves
in a mirror sometimes were not so successful, because they were bad
actors and would do things in a stiff way," he wrote.<br>
<br>
Nevertheless, some of the Disney animators looked down on the idea of
rotoscoping. One of them, Don Graham, derided the technique as a
"crutch" for artists who lacked the skill to do their work on their
own. Another, Grim Natwick, said that even when the artists used the
device, they used it only as the basis for their work, adding heavy
elaboration and even changing the proportions of the original filmed
figures. "We went beyond rotoscope," he said.<br>
<br>
But rival animator Walter Lantz criticized the look of the rotoscoped
work in "Snow White." In press materials for his own project, "Aladdin
and the Wonderful Lamp," Lantz declared he would use the rotoscope only
for timing because of what he saw as its limitations, especially in
Disney's film. "This literal system resulted in two faults -- a
jittering movement that contrasted with the fluidity of the animals,
and the fact that the human characters were too accurate to be seen
beside the caricatures," he said.<br>
<br>
Yet rotoscoping did help the artists on "Snow White" maintain a
consistency that might otherwise have been impossible. On earlier
animated shorts, each character was done by a single animator; as a
result, the characters had a unity of style. Because "Snow White" was
so extensive, however, more than one artist had to work on each
character. Working from live-action footage offered them the best way
to create a cohesive look.<br>
<br>
<font color="#990033"><b>Analog Rotoscoping for Visual Effects</b><br><br>
</font><img src="http://www.fxguide.com/modules/fxtips/files/art_of_roto/birds.jpg" alt="" align="left" border="0" height="210" hspace="5" vspace="5" width="275" border="0">While
the technique is useful for animation, rotoscoping eventually became an
important tool for visual effects in general. From the 1940s through
the 1960s, U.B. Iwerks, a well-known animator, turned to effects work,
where he pioneered the use of the rotoscope on films such as Alfred
Hitchcock's ?The Birds? (1963).<br>
<br> Rotoscoping in visual
effects was used primarily to make holdout mattes. "You frequently want
to composite different elements into the same shot to create that
shot," explained Tom Bertino, who was head of Industrial Light &
Magic?s rotoscoping department from 1987-93. "By using the tracing to
create black mattes, you can hold out certain elements."<br>
<br>
For example, Bertino imagines a scene of an explosion behind two people
on-screen, where the explosion is added after the fact. "You could
print the explosion over the frame. But you'd also cover up the
people," he said. "You'd need to isolate them with the rotoscope." To
make a traditional holdout matte, a rotoscope artist would trace the
figures that had to be isolated onto an animation cel. The outline
traced onto the cel then would be filled in with black paint, so that
it would block the appropriate section of the frame. "You create a
solid black matte," Bertino said. This black matte then could "hold
out" the part of the explosion image where the two people would appear,
so that when the two images were printed together, the people would
appear to be in front of the explosion.<br>
<br>
<img src="http://www.fxguide.com/modules/fxtips/files/art_of_roto/bertinoatwork.jpg" alt="" align="right" border="0" height="200" hspace="5" vspace="5" width="265" border="0">
Rotoscoping also could be used to stabilize a shaky film image. To do
stabilization, each film frame was rotoscoped onto an alignment chart.
A comparison of the charts allowed changes in position to be tracked
from frame to frame. Using this information, an optical copy of the
film could be made, with the printer offsetting the shifts in each
frame's movement.<br>
<br> Bertino said people underestimate the
difficulty of rotoscoping during the photochemical era: "It was a
painstaking process. There were so many moving parts to the rotoscope
camera, and so many places for things to get out of hand." Rather than
being a refuge for the unskilled artist, he added, rotoscoping was a
demanding craft. "The rotoscoper had to be a skilled animator to make
the line follow through. That's actually something that plagued some
early uses of the rotoscope as a special effects tool -- without actual
animators to handle it, it could get jittery."<br>
<br>
Good rotoscope artists were very precise about their work. "It was so
exacting," Bertino said. "It's almost like -- I don't know if you?ve
ever seen those incredibly detailed Chinese tapestries that they made
in the monasteries generations ago. They finally stopped making them
because the artisans would go blind. I'm surprised that more
rotoscopers didn't go that route."<br>
<br>
Jack Mongovan, a paint and rotoscope supervisor at ILM, began his
career in traditional rotoscoping and has been working in the field for
19 years. He remembers working in rooms that were completely dark
except for the light coming out of the projector. The rotoscope artists
were at the mercy of the painters who would later fill in their
outlines, and who could with a few stray brushstrokes outside the
outline make the image suddenly jittery. "I would never go back to
traditional for anything," Mongovan said.<br>
<br>
<font color="#990033"><b>Digital rotoscoping for Visual Effects</b><br><br></font>
Today, rotoscoping is done in the computer, using programs such as
Shake, FFI and Pinnacle Commotion. The shift to computer-based
rotoscoping began in the early 1990s with a software called Colorburst,
an image editing tool like Photoshop, that later evolved into Matador.
"When computers became prodigiously viable around here, right after the
'Terminator 2'/'Jurassic Park' era, we realized that the computer had
great capabilities for this," Bertino said. "It obviously became much
simpler."<br>
</p>
<div align="center">
</div>
<p><br>
Mongovan said that today, one rotoscope artist can do the same amount
of work that eight used to do, and in one quarter of the time. This is
often because in traditional rotoscoping, each frame had to be drawn
individually. The computer, on the other hand, can use the previous
frame as a basis, which means most of the drawing may already be done.<br>
<br>
Rotoscoping software works using splines, which are a series of points
connected by a line or curve. These splines are adjusted from frame to
frame, so that they continue to conform to whatever shape the artist is
tracing. Because rotoscoping software includes the tools to paint an
image, rotoscope artists now find themselves doing a lot of paint work
as well. "Rotoscoping is becoming the lesser part of what we do,"
Mongovan said. "We do so much more painting." Painting might mean
taking someone out of a shot, or replacing a sky, or painting out the
tennis balls used as visual effects tracking markers.<br>
<br>
Some skills remain necessary, including a sense of what is important.
"One of the hardest things for people to do in our department is to
realize that they're looking at a very zoomed-up plate," Mongovan said.
Also, he pointed out, a movie audience will see an image for only
1/24th of a second, too short a time to register flaws that may torture
the artists. More important is consistency. "I tell people, 'You can
paint that first frame wrong, just keep it wrong it all the way
through.'"<br>
</p>
<div align="center">
<p><img src="http://www.fxguide.com/modules/fxtips/files/art_of_roto/rotomk.jpg" alt="" border="0" height="242" width="350" border="0"><br>
</p>
</div>
<p>That
kind of understanding is key, Bertino agreed. "The secret to good
rotoscoping has always been -- regardless of what it's used for -- an
educated eye and good judgment as to what to include and what to leave
out," he said. "Most people think the rotoscope is very literal -- you
trace what's there, and that's it. It's possible to put too much detail
and confuse matters. You need to have that sense for judicious editing.
That hasn't changed at all. And not everybody's got that."<br>
<br>
<font color="#990033"><br>
</font></p>
<div align="left">
<p><font color="#990033"><b>Summary of Roto Tools</b><br>
</font></p>
</div>
<p><br>
<font color="#660000">
<b><a href="http://www.adobe.com/products/aftereffects/main.html" target="_blank" target="_blank">After Effects</a></b></font><br><br>
After Effects was the first tool to bring professional compositing
motion graphics and effects functionality to the desktop. After Effects
was originally developed by CoSA, then aquired by Aldus, which in turn
was aquired by Adobe. After Effects had very limited rotoscoping tools
in earlier versions, with only one rotospline and no paint tools, but
this is slowly changing. Version 4 added multiple rotosplines for
cutting mattes, version 5 added vector paint, and version 6.5 has added
cloning tools and tracker advancements (we still haven't tested these
improvements). It is still lacking b-splines as well as the realtime
roto performance found in more advanced roto tools like Commotion. Tip:
<a href="http://www.redgiantsoftware.com/commotionrotoimport.html" target="_blank" target="_blank">Red Giant software</a> offers a Commotion to AE roto import plugin<br>
<br>
<br>
<br>
<br>
<b><a href="http://www.discreet.com/products" target="_blank" target="_blank">Flint/Flame/Inferno/Fire/Smoke</a></b><br><br>
<img src="http://www.fxguide.com/modules/fxtips/files/art_of_roto/flame.jpg" alt="" align="left" border="0" height="221" hspace="5" vspace="5" width="394" border="0">Discreet?s
Advanced System, which include Flint, Flame, Inferno, Fire, and Smoke,
run on SGI workstations and range in price from $60,000 to over
$500,000. These products offer a complete post-production solution,
including very powerful and fast rotoscoping tools. The painting and
cloning tools are top notch, with excellent brushes and advanced
features including brushed based warping. The rotosplining
functionality is excellent, though not quite up to par with Commotion
due to a lack of b-splines and the inability to play spline over a
moving image in realtime. Tracking is very fast and very accurate. Many
facilities using Discreet?s advanced systems offset roto work to Macs
and PCs running Commotion, Shake or Combustion.<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
</p>
<p><br>
</p>
<p><b><a href="http://www4.discreet.com/combustion/" target="_blank" target="_blank">Combustion</a></b><br><br>
<img src="http://www.fxguide.com/modules/fxtips/files/art_of_roto/combustion.jpg" alt="" align="right" border="0" height="217" width="350" border="0">In
1997, Discreet aquired Paint and Effect from Denim Software. Paint
offered a vector based painting and cloning system for Mac and PC,
while Effect offered compositing capabilities. Discreet re-designed the
interfaces to make the applications more Discreet like, and merged the
two applications into Combustion. Along the way, they also replaced
some of the core functionality like Keying, Color Correction, and
Tracking with the same tool set found in Discreet?s Advanced Systems.
Combustion 2.0 added additional Advanced Systems features, including
the same rotosplines found in Flame. Combustion 3.0 took the product
even further with an edit operator, flash output and much more, most
significantly a flow diagram UI feature that many users feel more
comfortable working with. Combustion roto spline files can be opened
directly in the larger Inferno/flame/flint products.<br>
<br>
</p>
<p><br>
<br>
<br>
<br>
<br>
<br>
</p>
<p><br>
</p>
<p><b><a href="http://www.curious-software.com/products/gFx/" target="_blank" target="_blank">Curious gFx Pro</a></b><br><br>
<img src="http://www.fxguide.com/modules/fxtips/files/art_of_roto/gfx.jpg" alt="" align="left" border="0" height="211" width="350" border="0">gFx
is a relatively new product for the Mac OSX. Unlike other paint
programs it is designed around a stong user interface that fully
embraces moving footage, as such it can import, composite, track, or
stablise footage easily. The spline shapes can not yet be exported and
the product does not fully import Photoshop files and maintain their
structure, but this is planned for an upcoming release. the product
does have specialist wire removal tools and a very friendly and
interactive user interface. One of Curious's founders is the man behind
Parrallax, and it shows in some of the depth of tools already
available, 16bit raster paint with an excellent brush engine, and
b-spline rotosplines with an excellent transform points UI, motion blur
on splines, grouping splines, selective edge feathering (ie. advanced
gradient), and more.</p>
<p><br>
<br>
<br>
</p>
<p><br>
<br>
<br>
<br>
<br>
</p>
<p><b><a href="http://www.eyeonline.com/" target="_blank" target="_blank">Digital Fusion</a></b><br><br>
<img src="http://www.fxguide.com/modules/fxtips/files/art_of_roto/df_fullscreen.jpg" alt="" align="right" border="0" height="283" width="350" border="0">Digital
Fusion started in Sydney and moved to Toronto, Canada. At one stage a
version of Fusion was provided with Alias 3D - but today Eyeone has
gained one of the strongest postions in NT/Windows desktop compositing
solutions. Eyeon has two main products Digital Fusion and DFX +.<br>
Digital Fusion 4 is eyeon?s flagship product and marks the ninth major
release of this powerful compositor. DFX+ 4 is the 8-bit expandable
version of eyeon?s image processing software, Digital Fusion. DFX+ is
based on the architecture of DF4 and offers a number of significant
enhancements to its predecessor, DFX, including the flexible flow,
superior character generation, PSD import into separate layers for
animation, and more.<br>
Since Shake's move away from NT/Windows DF has provided a powerful cost effective solution.</p>
<p>
</p>
<p><br>
<br>
<br>
</p>
<p><br>
<br>
</p>
<p><b><a href="http://www.apple.com/shake" target="_blank" target="_blank">Shake</a></b><br>
<img src="http://www.fxguide.com/modules/fxtips/files/art_of_roto/shake2.jpg" alt="" align="left" border="0" height="270" width="350" border="0">Shake
has 3 options for Roto, Quickpaint, Quickshape, and Rotoshape.
Quickpaint is a procedural paint package inside Shake. You can paint
frame by frame and then view in realtime or paint with interpolation.
As all the paint elements can be animated over time it is a reasonable
roto tool. Quickshape is a basic roto tool, somewhat now completely
over shadowed by Rotoshape. Rotoshape allows variable edge softness and
logical operations between roto shapes. The rotos in Rotoshapes are
classic spline shapes with complex parent child relationships - and
velocity based motion blur. For complex rotoscoping this gives very
accurate results. Both Rotoshape and quickpaint can use shakes 2D
trackers. It is worth noting that given Shake is a node workflow model
it is possible to paint or roto through a track or image transform.<br>
</p>
<p><br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
</p>
<p><b><a href="http://www.adobe.com/products/photoshop/" target="_blank" target="_blank">Photoshop</a></b><br><br>
<img src="http://www.fxguide.com/modules/fxtips/files/art_of_roto/photoshop.jpg" alt="" align="right" border="0" height="196" width="350" border="0">The
most ubiquitous graphics application in the world was probably the
first digital rotoscoping tool to be used in film and video post
production. Though Photoshop was initially intended for still images,
it can work with motion by importing frames one at a time or importing
filmstrip files from video applications. Photoshop?s brush engine is
the benchmark everyone else strives for, and gives excellent control
when using pressure sensitive Wacom tablets. The biggest drawback is a
lack of a realtime preview of sequential frames. You will not know how
well your cloning is working out until you play back your clip in
realtime at full resolution. After painting numerous frames in
Photoshop, the sequence must be brought back into an editing or
compositing application such as Final Cut Pro to see realtime playback.
This is a painfully slow way of working. And since it isn?t intended
for video, it lacks travelling matte capabilities and motion tracking.<br>
</p>
<p>Other older products:</p>
<p><b><a href="http://www.pinnaclesys.com/ProductPage_n.asp?Product_ID=110&Langue_ID=7" target="_blank" target="_blank">Commotion</a></b><br>
<br>
Developed by Industrial Light and Magic Visual Effects Superviser Scott
Squires, Commotion was used for years at ILM before Scott formed Puffin
Designs and released it to the public. Commotion, then called Flipbook,
was often sighted at ILM and mistakenly referred to as the ?secret ILM
motion version of Photoshop?. Though Commotion looked very similar to
Photoshop in some respects, Commotion?s interface and tools were
designed for moving images, and was the first tool on the desktop to
offer realtime ram based playback. This realtime core functionality was
the foundation for all of the roto tools added as the product
developed. Advanced roto tools include raster based paint, spatial and
temporal cloning, wire removal tools, auto-paint, unlimited bezier and
natural cubic b-splines, motion blur on rotosplines, and a very fast
and accurate motion tracker. Commotion quickly became the de-facto roto
tool in the industry, replacing Matador in most post facilities. Puffin
Designs was aquired by Pinnacle Systems in 2000, but sadly development
has stopped on the product, most if not all the original developers has
long since left and no new work has really been done on the product in
the last 3 years. Importantly Commotion curves can be exported and
imported into AfterEffects, see AE above.<br>
<br>
</p>
<p><b><a href="http://www.softimage.com/Products/Other/Matador/Product_Info/matador/index.htm" target="_blank" target="_blank">Matador</a></b><br><br>
Matador was originally developed by Brittish developer Parralax, and
acquired by Avid along with Parralax? compositing application Illusion.
Available only on the SGI platform and priced around $15,000, Matador
was one of the first digital rotoscoping tools which gained a wide
acceptance in the film post production pipeline. Matador started as a
tool made for editing still images, so many of the tools used for
motion work were not well thought out. Matador provides excellent matte
creation tools including b-splines, motion tracking, and a full set of
painting and cloning tools, with full 16bit/channel support. Avid
stopped development of Matador in the late 90?s. The original
developers tried to spin it off into a new company called ?Blue?, but
that never took off.<br>
There are new Roto tools that have now been incorporated into Softimage
XSI compositor in V.4, but these are not Matador - as many people
believe.<br>
</p>
<p><b><a href="http://www.newtek.com/" target="_blank" target="_blank">Aura</a></b><br>
<br>
Newtek is mostly known for their 3D application Lightwave. Aura was a
stand-alone paint application designed for film and video. It hasn?t
become widely accepted in the industry, and mostly used by Lightwave
users to finesse 3D renders. Some advanced features include a
16bit/channel paint engine, and auto-paint. Newtek has now stopped
supporting the program and as of June 2003 with Lightwave 3D 7.5 -
Newtek offers DFX+ at no additional cost.<br>
<br>
<b><a href="http://www.media100.com/" target="_blank" target="_blank">Roto DV</a></b><br>
<br>
Originally developed as a product named ?Roto? by a failed start-up
company called Post Digital, Roto DV was aquired by Radius, which later
turned it?s name into Digital Origin, and then was aquired by Media100.
Though it was called Roto, it actually didn?t have very sophisticated
roto tools, and the ones that were actually pretty cool never made it
into the shipping product. Media100 has no information on their website
about this product, so we assume it is no longer developed or supported.<br>
</p>
<div align="left">
<p><br>
<font color="#990033"><b>Rotoscoping in the modern post-production pipeline.<br>
</b></font></p>
</div>
<p><br>
<font color="#660000"><b>Effects Painting<br><br>
</b></font>Effects
Painting is generally used to quickly add new elements to a scene.
Instead of creating elaborate particle effects in 3D simulation
software like Maya, many effects can be done faster by a skilled artist
using a paintbrush or airbrush in a paint application. Effects like
lightning or light-sabres can be painted one frame at a time. More
advanced roto tools offer auto-paint capabilities which allow you to
record brush strokes and then play them back over a selected range of
frames. Some roto applications also allow you to add jitter to the
brushes, as well as add the ability to paint the stroke out over time.<br>
<br>
There are two types of paint engines used in modern graphics
applications; Bitmap (also known as raster) and Vector. Raster paint
engines are destructive in the sense that they replace the pixels being
painted onto with the color from the paint stroke. Photoshop,
Commotion, and Flame are raster based applications. This is a very fast
way of working since the frame is immediately updated and the results
can be played back in real time without rendering. Vector based paint
engines, like Illustrator, Shake, After Effects Vector Paint, or
Combustion, use points and splines to define a brush stroke, and do not
destroy the underlying pixels. This non-destructive process allows you
to edit paint strokes at any time, though you pay the price in speed
since the strokes need to be rendered before they can be previewed in
realtime. The other disadvantage is that hundreds of channels will be
created with the spline information even if you do not plan on using
them.<br>
<br>
<font color="#660000"><b>Cloning/Paint Touch-Up<br><br>
</b></font>Most
paint work done in the rotoscoping process is used for touching up film
or video footage. This includes removing wires and rigs, removing
logos, dust busting, scratch removal, etc. In these circumstances, the
roto tool must be able to provide temporal and spatial cloning. Spatial
cloning is a type of cloning which takes pixels from one position of
the frame, and paints the source onto another position on the frame.
Photoshop?s rubber stamp tool is an example of spatial cloning.
Temporal cloning allows you to paint pixels from one frame in a
sequence to another frame. Commotion?s Super Clone tool is an example
of temporal cloning. A good roto tool should provide both of these
options together so users can offset position and frame number
together. Other cloning tools include wire removal tools which allow
you to draw a line to zip out a wire. Typically, wire removal tools
clone pixels from a specified value on either side of the line, then
smear the outside pixels together to cover up the wire or scratch. More
advance wire removal tools will add advanced cloning techniques to the
wire removal process. For example, Commotion looks at a specified
number of pixels on either side of the line, flips those pixel values
then cross dissolves to cover up the wire.<br> There are excellent
specialist plugin tools for wire removal such as Tinder's Furnace
plugins for Shake and discreet's inferno or flame<br>
<br>
<b><font color="#660000">Matte creation (Keying, Rotosplining, Painting)<br><br>
</font></b>Creating
hold-out mattes, sometimes referred to as masks or alpha channels, is a
major piece of the compositing process. A matte is a grayscale clip
which is used to stencil portions of the background footage. Anything
in the black area will be obscured, and anything in the white area will
show through (in some systems like Avid this is backwards). Any gray
area in the matte will be semi-transparent. Roto artists are expected
to cut precise mattes with consistent edges which will not chatter. If
the matte is sloppy, the shot will look fake. The best compositor will
produce unacceptable work if provided with poor mattes. Mattes can be
created with three different techniques; Extraction, Rotosplining, and
Painting. For most situations a combination of these three techniques
will have to be used.<br>
<br> Extraction is the process of
procedurally generating a black and white matte. This can be done by
shooting an element against a blue or green screen, then using a color
keyer to knock out the specified color. Sometimes bluescreens are not
practical, and in these cases other types of extractions need to be
performed. Luminance keying can extract a matte based on the luminance
values of the source. Either dark or light areas can be extracted into
a matte. An image can be de-saturated then leveled to create a high
contrast matte. Sometimes it is better to start with one of the color
channels to create an extraction. It is always a good idea to check out
each color channel to see how the contrast looks, then pick the best
one to start leveling into a high contrast matte. The Shift Channels
filter in AE or Commotion can shift one of these color channels into
the Alpha Channel, which can then be leveled into the final matte.
Another type of extraction is Difference Keying, which generates a
matte based on differences between two clips.<br>
<br>
Rotosplining is the process of creating vector shapes to manually cut
an element out of it?s background. These shapes can be re-positioned on
various keyframes, and the software will interpolate the in-betweens.
The process isn?t as automatic as an Extraction, but at least the
computer can interpolate some of the frames for you. Good roto tools
will offer multiple rotosplines with the ability to keyframe each shape
separately. By using multiple splines, complex elements can be cut out
from their background. For example, an actor running would have
separate shapes for the hand, forearm, upper arm, chest, torso, thigh,
shin, etc. By breaking the shapes down into smaller elements, it is
much faster to set the keyframes by moving the shape and not individual
points, and the software will interpolate much more accurately.
Commotion has the most advanced rotosplining tools on the market. Most
applications use bezier splines for their rotosplines, which require
tweaking both the points and the handles. Commotion has bezier splines,
but the real power is in the B-Splines, which are much easier to
control. B-Spline, also called Natural Splines, do not have the handles
found on Beziers. Instead they always create a curved surface depending
on how far apart the points are. The points default to an average
tolerance, and can be interactively changed to loosen or tighten the
curve. B-Splines are consistently faster and easier to work with than
beziers. Commotion also has the ability to play multiple shapes in
realtime over the background footage. This allows you to quickly
preview how your shapes are animating compared to the source footage.
Other important functions found in Commotion?s rotosplining tools
include directional feathering, unlimited splines, color coding and
naming splines, motion blurred mattes based on direction and velocity
of the splines, a curve editor for fine tuning the motion between
keyframes, rotating and scaling splines and selected points, global
position offsets, and composite previews.<br>
<br>
Mattes can also be generated with paint tools. This is generally the
last resort, as painting mattes generally will produce inconsistent
results due to the fact that every frame needs to be painted on.
Auto-paint functionality can help with this consistency problem, but
for the most part painting mattes should be left for final tweaking of
an extracted or rotosplined matte. Advanced rotoscoping tools offer the
ability to paint mattes directly into the Alpha Channel while
continuing to see an overlay of your RGB channel. This is sometimes
referred to as a Mask Overlay, or QuickMask, and is crucial for
painting complex mattes.<br>
<br>
<b><font color="#660000">Motion Tracking<br>
</font></b>Motion
Tracking is a computer based process which analyzes a pixel or
sub-pixel in a clip, and follows that pixel or sub-pixel to find the
exact coordinates on each frame. There are two primary uses for motion
tracking. The first is for stabilization, and the second is for match
moving.<br>
<br> Once a motion tracker knows where a sub-pixel is
on every frame, it can re-position the image on every frame in the
opposite direction to counteract a camera shake. This stabilization
process works fantastic in most cases. Tracking one point allows you to
stabilize position. Adding a second tracker will allow the software to
compare the relative positions of the two trackers, which can also
stabilize rotation and/or scale.<br>
</p>
<div align="center">
<p><img src="http://www.fxguide.com/modules/fxtips/files/art_of_roto/df_tracker.jpg" alt="" border="0" height="222" width="350" border="0"></p>
</div>
<p><br>
The second use for motion tracking is match moving. If you needed to
add a logo to a car door, you can track the handle on the door, then
apply that data to a logo on another layer. As mentioned above, a
second tracker can be added to match move a logo which needs to rotate
and/or scale. If perspective changes, four point tracking can be used
to track four points. Each tracker can then be assigned to a corner of
a CornerPin filter applied to the image.<br>
<br>
Serious roto tools need motion tracking to help automate tedious
processes, as well as to produce convincing results. Motion trackers
should allow you to track 1, 2, and 4 points simultaneously. Advanced
trackers, like the one found in Commotion, allow for unlimited point
tracking, and access to the tracked data in text format so it can
easily be used in other applications (Commotion can export text, as
well as data formatted for AE, Flame, Digital Fusion, Electric Image,
and other apps). Motion trackers should also allow you to apply the
tracking data to rotosplines and individual points on a rotospline for
automated matte creation, as well as attaching tracker data to paint
and cloning tools. And most importantly, the motion tracker has to be
accurate. Flame, Shake, Digital Fusion and Commotion have the fastest,
most accurate trackers.<br>
</p>
<div align="center">
<p><img src="http://www.fxguide.com/modules/fxtips/files/art_of_roto/boujoubullet.jpg" alt="" border="0" height="286" width="350" border="0"></p>
</div>
There
are excellent program for 3 dimensional camera tracking but these are
rarely used for roto, however programs such as boujou and boujou bullet
will import b/w rotos to aid in tracking<br>