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morph_tut8
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\ApAssist
\: - This is the Quick Help for the special effects warp morph panel -
\: ---------------------------------------------------------------------
\: Written by David E. Patterson
\: ---------------------------------------------------------------------
\font topaz.font 8
\tc 1
\wr
\lj
\dd "imh_descriptor"
\node "morph_cmtools"
\title "More on Morphing - Compose Morphing Frames, Points, and Edges"
\next "morph_tut9/morph_cmm"
\prev "morph_tut7/morph_ctools"
\{ \ra \image "Clips/Bullet2.pic" l 0 \cap
\{ \ts bu Morphing and Frames\} \} \flushimage
When we speak of frames with regard to dual-image morphing, we are referring
to the concept that many morphs are intended to be animated. Because of
this, the morphs would be performed over a series of intermediate frames
where the effect is slightly more complete in each of the frames. For
instance, when someone says thay are creating a 15-frame dual-image morph,
the idea they are conveying is that in frame 15, the morph has fully
converted from the starting image to the ending image. In frame 8, the middle
frame, the effect would be a 50% mix of both frames, and so on for each
intermediate frame. When a sequence of frames are rendered, the "flow" of
the surfaces of the images under control of the points and edges is apparent
as the frames are viewed in series.
When the object of a dual-image morph is a single final image and not a
sequence of images, the convention is to assume that the desired image is the
middle image of a sequence (of any length). As an example, if \{ \ts b
Imagemaster R/t \} has been set for a 15-frame sequence, rendering frame 8
will provide a result with the mix of the two images most obvious.
\{ \ts b Imagemaster R/t \} allows you to choose a frame from anywhere within
the currently set sequence length when you render a single frame instead of a
sequence of frames. Simply remember that when you are creating a single frame
result of a dual-image morph you should set the frame to be rendered to be
the middle of the length of the sequence. This is done in the \{ \ts i \tc
10 Do 1 Frame \} control panel, which is described in more detail later.
\{ \ra \image "Clips/Bullet2.pic" l 0 \cap
\{ \ts bu Points\} \} \flushimage
Control points are used to define the flow of the image surface over the
frames of a morph; when the object is one single image instead of a sequence,
you should still think of the control points this way - it's just that you're
only interested in the middle frame of the sequence. The start point defines
the portion of the image that will be moved, and the end point defines the
location for that portion of the image for the final frame of the morph.
Control points can be thought of in two ways. First, and most conveniently,
as a series of pairs of points, just as you see them in the main dual-window
interface.
Secondly, you can consider the two points as the endpoints of a path, over
which the images must \{ \ts i flow \} to accomplish the changes you are
specifying with the points. You can actually see these paths in the \{ \ts i
\tc 10 Arc Vectors \} window.
It is not strictly correct to think of control points as the endpoints of
vectors, for \{ \ts b Imagemaster R/t \} can make the course between the two
points a complex curve instead of a straight line. That is why you should
think of them as paths, rather than vectors. The default course between two
points is a straight line (vector). Extension from a vector to a more complex
path is done in the \{ \ts i \tc 10 Arc Vectors \} interface, where you can
\{ \ts i grab \} the vector and shape it into a curve. This is described in
more detail in the portion of this document that describes the \{ \ts i \tc
10 Arc Vectors \} control panel.
Placement of points should be done such that they are deposited at all key
corresponding locations on the two image's surfaces. If we take the case of a
face as an example, the corners of the eyes and mouth are obvious candidates.
In addition, placement of points regularly along the edge of the profile will
help control the images more exactly.
Points are never discarded by \{ \ts b Imagemaster R/t\} 's morphing
procedures, even if they are defined in a conflicting manner. For this
reason, you need to be careful that you do not place your points in such a
way as to cause a conflict - one example of this is when the paths of two
points cross each other during the course of a morph. This, and similar
situations, will create folding and/or tearing in the image. Often you will
find it easy to determine if such a condition exists by observing the paths
defined by the endpoints in the \{ \ts i \tc 10 Arc Vectors \} interface.
Points cannot completely restrain an image, because they only exactly control
the portion of the images directly underneath where they are placed. Areas of
the images which are not directly underneath a point (or an edge) are
adjusted according to the motions of the points which are nearest. Even
points which are quite far away may add motion to an otherwise uncontrolled
region. When a portion of an image needs more exact control, you should use
points in conjunction with edges, described next.
\{ \ra \image "Clips/Bullet2.pic" l 0 \cap
\{ \ts bu Edges\} \} \flushimage
Edges are similar to points in that they specify movement for the surface of
the image. They differ in that they control a much larger region, the entire
area exactly under the line.
Edges also differ in that \{ \ts b Imagemaster R/t\} 's morphing procedures
may discard an edge under certain circumstances, such as when two edges are
defined that cross each other. When creating edges, you should take care to
ensure that you do not create a situation like this, as the results are
undefined and will result in the images tearing or folding.
Placement of edges should generally be done along lines in the images such as
the edges of eyes or a profile. They will restrict the motion of the image's
surface such that image data will not be transferred across the line,
retaining colors precisely within the regions which are bounded by edges.
Most high-quality morphs will use almost as many edges as they do points.
\{ \ra \image "Clips/Bullet2.pic" l 0 \cap
\{ \ts bu Morphing Time\} \} \flushimage
The time it takes \{ \ts b Imagemaster R/t \} to generate morph output frames
is based almost entirely upon the size of the output images in the sequence.
Anti-aliasing also adds a certain amount of time to the generation of each
frame, again directly proportional to the size of the output image. A small
amount of additional time is needed to compute frames that contain custom
point-velocity computations. The size of the input images has no effect (and
they may even be different resolutions, also with no effect on time); \{ \ts
b Imagemaster R/t \} always scales images as needed during operations.
\endnode