vfx class notes 2/9: rotoscoping and compositingcompositing
-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.