vfx notes 2/23: 3d tracking
possible to derive point data for scene reconstruction from photography
2 types of tracking:
1. CAMERA TRACKING
-re-establishes position of camera in 3d space.
-allows locking of moving 3d objects into static live-action scene.
-allows set extension of static live-action object.
2. OBJECT TRACKING
-re-establishes motion of object in action in 3d space
-allows locking of 3d objects onto moving live-action objects.
use boujou for motion tracking. for camera tracking it is easy! not as easy for object tracking.
Tuesday, May 12, 2009
vfx notes 3
vfx class notes 2/9: rotoscoping and compositing
compositing
-prepping incoming elements ie. color correction, stabilize, dust
-modifying elements ie. transform, dewarping, lens distortion
-keying mattes from green screen plates
-assembly of elements- overs, adds, multiplies
-adding effects ie. haze, blur, film grain, flares
-prepping for film output, setting LUT grain match.
-can be be highly creative or assembly line tedium
becoming more 3d-like in scope. nuke contains a 3d renderer and camera!
application for compositing: NUKE!
-node-based, not centrally time based like AfterEffects
-more efficient, faster, capable of large production work
-very creative workflow, but you need to know technical aspects of the images used.
-developed by digital domain 15 years ago
-very fast. UI not as accessible but it's getting better.
basic comp skills we'll cover:
-Nuke UI
-image formats
-merge operations
-color corrections
-keying green screen
-roto
rotoscoping
-cutting mattes manually
-necessary when green screen was or could not be used in the shoot.
-often necessary from location plates
-sky replacement a typical use.
in rotoscoping, you never want a sharp edge - about a 2 pixel blur.
NUKE NOTES
open session = "script"
right click for file menu
image -- read (hotkey R)
find footage
floating thumbnail node - drag from viewer 1 to thumbnail
for viewing - render - flipbook selected
pencil icon: bezier (make sure it's clicked)
(tapping space bar - fullscreens whichever window is selected)
hold down ctrl+alt to put down pen points. creates a white shape. in bezier tools window (right side of screen) adjust output. uncheck RGB but leave alpha channel.
change channels at top of viewer window.
right click and convert vertices to cusp (also can smooth, break) - turns into a rectangle.
alt+ctrl to add another point
hit "A" in viewer to see alpha channel
ctrl + drag pts to feather just one part.
automatically has autokey on.
select 2 pts. + handle to move, rotate, scale both together
set keyframes and it interpolates between
set proxy mode to speed up playback
once done, detach image from viewer, so you just have alpha channel of the final bezier.
rendering - little film frame - click on it!
"w" to write
click on folder on right
decide what to name it
make adjustments
"render" dialogue box: "1, 133" means to render between frames 1-133.
naming: foo.%04d.jpg
save scripts as nk file.
vfx notes 2
vfx classnotes 2/2
vfx shot vs. standard shot
-can't be accomplished thru standard photography
-needs repair of problems
-needs addition of other elements (pyrotechnics, etc.)
-typically very expensive: $4000/sec.
storyboard to identify vfx - necessary shots
early in-camera techniques:
-split screen
-forced perspective
-stop action
-adjusting speed
-double exposure/ traveling mattes
-miniatures
vista vision (aka. 8 perf): rotate 35mm for bigger frame. sacrifice sound.
rear projection: gateweave causes jitter in rear projected bg.
-double grain from shooting projected film
front projection: scotch-lite = what screens are made of. same thigns as stop signs.
optical printing: pre-exposed film and mattes to composite images.
matte painting: done on glass in front of shot - lighting changes through day, so make ambiguous light and shadows. still, image loses life so.... VFX to bring it back!
paralax: relative motion of objects in relation to camera. things close to you move fast!
vfx shot vs. standard shot
-can't be accomplished thru standard photography
-needs repair of problems
-needs addition of other elements (pyrotechnics, etc.)
-typically very expensive: $4000/sec.
storyboard to identify vfx - necessary shots
early in-camera techniques:
-split screen
-forced perspective
-stop action
-adjusting speed
-double exposure/ traveling mattes
-miniatures
vista vision (aka. 8 perf): rotate 35mm for bigger frame. sacrifice sound.
rear projection: gateweave causes jitter in rear projected bg.
-double grain from shooting projected film
front projection: scotch-lite = what screens are made of. same thigns as stop signs.
optical printing: pre-exposed film and mattes to composite images.
matte painting: done on glass in front of shot - lighting changes through day, so make ambiguous light and shadows. still, image loses life so.... VFX to bring it back!
paralax: relative motion of objects in relation to camera. things close to you move fast!
ARTifact notes 1
this was my first attempt at recreating the look of compression artifacting. i started in photoshop, developing a stylized version of this pixelated look with still frames from youtube videos. the plan was to then move into aftereffects and create the result over time. here are two of the still images i created.
when i moved into after effects, the results were far less successful. i was key-framing this "mosaic" filter by pixel size and layering varying animations over rotoscoped youtube clips. i was hoping for something akin to these still images, in their subtle layers of ghostly pixels, where the image digitally melts out of the frame. but moving over time, it was chaotic and completely ungraceful. it looked awful. so awful infact, that i apparently erased all evidence of it from my computer. but i do have some notes of my workflow on record:
image height: 720
copy layer
levels: R = 160
copy again
filter: mosaic 17
cut out around both
less pixely layer on top: "darken" blend mode.
notes on my notes
i have decided to post my notes from vfx, both because going through them again will help me better absorb the information, and because it is honest documentation of all that i've learned this semester.
while i was learning maya and nuke in eric's class, i was also trying to learn how to exploit youtube-quality video for its characteristic blocky, compressed, artifacted look. so i will be interjecting my class notes with my independant research on how to acheive this compression effect intentionally and artistically. these will be posted in the order they were recorded/learned.
while i was learning maya and nuke in eric's class, i was also trying to learn how to exploit youtube-quality video for its characteristic blocky, compressed, artifacted look. so i will be interjecting my class notes with my independant research on how to acheive this compression effect intentionally and artistically. these will be posted in the order they were recorded/learned.
vfx notes 1
vfx class notes 1/26: vfx history and maya basics.
types of effects:
special - explosions, etc (on camera)
visual - post production (usually computer, but can also be practical)
practical - physical
keyboard shortcuts:
translate = w
rotate = e
scale = r
IPR render allows you to see any updates between renders
marking menu
channels box
mel commands - script commands
ctrl A = attribute editor
edit - delete (by type or all) -- use for modeling
display menu - hide menu allows you to hide particular elements
window - general editor, script editor, hyershade
render settings - export as frames (tifs)
"frame padding" = number of digits assigned to file name
4 = 0003, 2 = 03, etc.
when lighting, always uncheck "enable default lights"
types of effects:
special - explosions, etc (on camera)
visual - post production (usually computer, but can also be practical)
practical - physical
keyboard shortcuts:
translate = w
rotate = e
scale = r
IPR render allows you to see any updates between renders
marking menu
channels box
mel commands - script commands
ctrl A = attribute editor
edit - delete (by type or all) -- use for modeling
display menu - hide menu allows you to hide particular elements
window - general editor, script editor, hyershade
render settings - export as frames (tifs)
"frame padding" = number of digits assigned to file name
4 = 0003, 2 = 03, etc.
when lighting, always uncheck "enable default lights"
Monday, May 11, 2009
appropriate! (the verb, not the adjective)
coming into this semester, i was immensely interested in using found footage combined with real objects. appropriation in general is very appealing to me. from recycling would-be trash (cereal boxes, dead light bulbs, etc.) to long-lost commercials found on youtube, i find it challenging, exciting, and rewarding to make new art from old crap.
i'm a collector, or a pack-rat if you want to call me names. i hold on to things forever, thinking there might be a use for them some time down the road. (and the occasional truth of this philosophy is why i just continue to amass all this junk.) furthermore, we as humans are continuously told to "reuse! recycle!" lest we bury ourselves in our own consumer by-products. i find this sentiment particularly poignant as we enter this age of disposable media, wherein we're virtually buried, or oversaturated, by online EVERYTHING. i think my brain melts a little in such instances where i go on ebay and buy the old taperecorder that someone held onto for 30 years, thinking that i'll use it to make some new work of art, only to learn that i can't because it doesn't work properly, but man it looks cool, so i should keep it just in case i want to put it on display when i one day have a shelf for it, but it did come in that sturdy box that i'll kick around my dining room floor until i use it to make a set for a different animation which i will capture digitally and put online for someone to find and download and clutter up their harddrive until they eventually put it in the "recycle bin," which ironically permanently erases it.
seriously, i find these connections very fascinating. of course, the more i try to develop imagery with found materials, the more i become aware of the limitations:
1. inflexibility - getting pre-existing objects and video to do something new. i am referring here to visual "newness," as opposed to perceptual newness that i feel is almost automatically achieved through juxtaposition of disparate, found elements. i seek to manipule the video and objects so that they embody the fluidity and dynamism of animation, while maintaining their original appeal.
2. integrating set video into a scene - getting found video to look like something other than a window of youtube within a bigger frame, and i don't mean just putting an afterEffects filter over it! old video has as much evocative power as old toys, electronics, and other objects. however, i think it's a whole other challenge to create original, moving imagery from pre-exisiting, moving images.
3. actually acquiring the exact objects that i imagine - for example, i would love to create imagery with one of those late 70s/early 80s tv with wood-paneled sides and big silver knobs. however, i am having a surprisingly hard time finding one for purchase. apparently no one wants to pay shipping for an item that size.
so... i thought i would look to Eric's class for potential ways to get around these limitations. visual effects is the blending of separate elements into a whole new, seamless scene. i love that the industry's history is rooted in magic and visual trickery and making things happen that no one had ever seen before.
i'm a collector, or a pack-rat if you want to call me names. i hold on to things forever, thinking there might be a use for them some time down the road. (and the occasional truth of this philosophy is why i just continue to amass all this junk.) furthermore, we as humans are continuously told to "reuse! recycle!" lest we bury ourselves in our own consumer by-products. i find this sentiment particularly poignant as we enter this age of disposable media, wherein we're virtually buried, or oversaturated, by online EVERYTHING. i think my brain melts a little in such instances where i go on ebay and buy the old taperecorder that someone held onto for 30 years, thinking that i'll use it to make some new work of art, only to learn that i can't because it doesn't work properly, but man it looks cool, so i should keep it just in case i want to put it on display when i one day have a shelf for it, but it did come in that sturdy box that i'll kick around my dining room floor until i use it to make a set for a different animation which i will capture digitally and put online for someone to find and download and clutter up their harddrive until they eventually put it in the "recycle bin," which ironically permanently erases it.
seriously, i find these connections very fascinating. of course, the more i try to develop imagery with found materials, the more i become aware of the limitations:
1. inflexibility - getting pre-existing objects and video to do something new. i am referring here to visual "newness," as opposed to perceptual newness that i feel is almost automatically achieved through juxtaposition of disparate, found elements. i seek to manipule the video and objects so that they embody the fluidity and dynamism of animation, while maintaining their original appeal.
2. integrating set video into a scene - getting found video to look like something other than a window of youtube within a bigger frame, and i don't mean just putting an afterEffects filter over it! old video has as much evocative power as old toys, electronics, and other objects. however, i think it's a whole other challenge to create original, moving imagery from pre-exisiting, moving images.
3. actually acquiring the exact objects that i imagine - for example, i would love to create imagery with one of those late 70s/early 80s tv with wood-paneled sides and big silver knobs. however, i am having a surprisingly hard time finding one for purchase. apparently no one wants to pay shipping for an item that size.
so... i thought i would look to Eric's class for potential ways to get around these limitations. visual effects is the blending of separate elements into a whole new, seamless scene. i love that the industry's history is rooted in magic and visual trickery and making things happen that no one had ever seen before.
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