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morph_tut4
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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_mwtools"
\title "More on Warp Morphing - Frames, Points, and Edges"
\next "morph_tut5/morph_wmm"
\prev "morph_tut3/morph_wtools"
\{ \ra \image "Clips/Bullet2.pic" l 0 \cap
\{ \ts bu Warp Morphing and Frame\} \} \flushimage
When we speak of frames with regard to warp 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 apparent in each of the frames. For instance, when
someone says thay are creating a 15-frame warp morph, the idea they are
conveying is that in frame 15, the effect of the morph is fully apparent. In
frame 8, the middle frame, the effect would be 50% of the final result, and
so on for each intermediate frame. When a sequence of frames are rendered,
the "flow" of the surface of the image under control of the points and edges
is apparent as the frames are viewed in series.
When the object of the morph is a single final image and not a sequence of
images, the convention is to assume that the desired image is the final image
of a sequence (of any length). As an example, if \{ \ts b Imagemaster R/t \}
has been set for a 17-frame sequence, rendering frame 17 will provide a
result with the effect 100% apparent. \{ \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 warped image you should set the frame to
be rendered to be the same as the length of the sequence. This is done in the
\{ \ts i \tc 10 Do 1 Frame \} control panel.
\{ \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 warped 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 last 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 image must "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 image surface. 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 image 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 image directly underneath where they are placed. Areas of
the image 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 image tearing or folding.
Placement of edges should generally be done along lines in the image such as
the edges of eyes or a profile. They will restrict the motion of the image
surface such that it will not transfer image data 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