[Mata]

thank you very much sir

[Mata]

double post but... i tried looking up ways of copying keyframes for roto. I have a shot where its slowed down so i have 2 frames that are the same (a decent amount). Right now I have 30 beziers and copying each individually is a little time consuming. I'm trying to speed up the process if anyone has a gizmo or another technique that'll help this out. Thanks guys

[sri2128]

really awesome stuff Mr.Aruna

[perkyviky]

#1 ARTICULATED ROTOS
Things can get messy when rotoscoping a complex moving object such as a person
walking. Trying to encompass an entire character with crossing legs and swinging
arms into a single shape like the one used for the cat in Figure 6-13 quickly becomes
unmanageable. A better strategy is to break the roto into several separate shapes,
which can then be moved and reshaped independently. Many compositing programs
also allow these separate shapes to be linked into hierarchical groups where one shape
is the “child” of another. When the parent shape is moved, the child shape moves
with it. This creates a “skeleton” with moveable joints and segments rather like the
target object. This is more effi cient than dragging every single control point individually
to redefi ne the outline of the target. When the roto is a collection of jointed
shapes like this, it is referred to as an articulated roto.

#2 INTERPOLATION
Time to talk temporal. Temporal, of course, refers to time. Since rotos are a frameby-
frame animation, time and timing are very important. One of the breakthroughs
that computers brought to rotoscoping, as we have seen, is the use of splines to defi ne
a shape. How infi nitely fi ner to adjust a few control points to create a smooth line
that contours perfectly around a curved edge, rather than to draw it by hand with a
pencil or ink pen. The second, even bigger breakthrough is the ability of the computer
to interpolate the shapes, where the shape is only defi ned on selected keyframes,
and then the computer calculates the in-between (interpolated) shapes for
you.

#3 KEYFRAMES
In the previous discussion about shape interpolation, the concept of the keyframe
was introduced. There are many keyframing strategies one may use, and choosing
the right one can save time and improve the quality of the fi nished roto. What follows
is a description of various keyframe strategies with tips on how you might choose
the right one for a given shot.

#3.1 On 2’s
A classic and oft used keyframe strategy is to keyframe on 2’s, which means to make
a keyframe at every other frame—that is, frame 1, 3, 5, 7, and so forth. The labor
is cut in half and the computer smoothes the roto animation by interpolating nicely
in between each keyframe. Of course, each interpolated frame has to be inspected
Figure 6-20 Keyframes with interpolated frames.
Keyframe 1 Interpolated
frame 1
Interpolated
frame 2
Interpolated
frame 3
Keyframe 2
Rotoscoping 109
and any off-target control points must be nudged into position. The type of target
where keyframing on 2’s works best would be something like a walking character
shown in the example in Figure 6-21. The action is fairly regular, and there are constant
shape changes, so frequent keyframes are required.

#3.2 Bifurcation
Another keyframing strategy is bifurcation, which simply means to fork or divide
into two. The idea is to create a keyframe at the fi rst and last frames of a shot, then
1 2 3 4 5 6 7 8 9 10
110 Compositing Visual Effects
go to the middle of the shot and create a keyframe halfway between them. You then
go mid-way between the fi rst keyframe and the middle keyframe and create a new
keyframe there, then repeat that for the last frame and middle frame, and keep subdividing
the shot by placing keyframes midway between the others until there are
enough keyframes to keep the roto on target.

[Gravy]

Are you not going to tell us what book that is from?