Presentation FIT'11 Sarfraz
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Transcript of Presentation FIT'11 Sarfraz
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8/3/2019 Presentation FIT'11 Sarfraz
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KuwaitKuwaitUniversitUniversit
Muhammad SarfrazDepartment of Information Science
Kuwait University, Kuwait
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8/3/2019 Presentation FIT'11 Sarfraz
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KuwaitKuwaitUniversitUniversit
` Motion Data video games, computer animation, animated videos
` Motion tweening is the process of generatingintermediate frames between keyframes tocreate an illusion of motion
` A simple and efficient method of tweening of
motion data for skeletal animations using cubicCardinal spline.
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8/3/2019 Presentation FIT'11 Sarfraz
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KuwaitKuwaitUniversitUniversit
` Skeleton
` Bone
` Channel or Degree ofFreedom (DOF)
` Frame/Frame-rate
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8/3/2019 Presentation FIT'11 Sarfraz
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KuwaitKuwaitUniversitUniversit
We can plot the motion data
of a joint for each channel
separately such that:
frame numbers are along
horizontal axis translation or rotation
values are along vertical
axis.
This kind of plot is called
motion curve ofmotion
signal.
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8/3/2019 Presentation FIT'11 Sarfraz
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KuwaitKuwaitUniversitUniversit
` BVH (Bio Vision Hierarchy) fileformat. This format is simple andsupported by many motioncapture devices and animationprograms.
` A BVH file has two sections: header section describes the initial
hierarchy of the skeleton data section contains motion data.
BVH can store motion for ahierarchical skeleton
` motion of the child bone is directlydependent on the motion of theparent bone.
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8/3/2019 Presentation FIT'11 Sarfraz
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KuwaitKuwaitUniversitUniversit
` Cardinal spline is a C1
continuous curve.` A Cardinal spline segment, is
defined by four control points,i.e., Pj-1, Pj, Pj+1 and Pj+2.
` The j th segment of Cardinalspline interpolates betweentwo middle control points, i.e.,Pjand Pj+1.
` The end control points, i.e., Pj-1 and Pj+2 are used tocalculate the tangents at Pjand Pj+1.
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8/3/2019 Presentation FIT'11 Sarfraz
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KuwaitKuwaitUniversitUniversit
` Equation of Cardinal spline forj th segment
2
23
1
23
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23
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8/3/2019 Presentation FIT'11 Sarfraz
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KuwaitKuwaitUniversitUniversit
` Motion tweening of a single channel of a joint.
` Objective is to generate smooth animation usin
few keyframes
` Initially the user has to specify the keyframes`All the keyframes and their in-between frames
constitute a complete motion curve of the
channel.
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8/3/2019 Presentation FIT'11 Sarfraz
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KuwaitKuwaitUniversitUniversit
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8/3/2019 Presentation FIT'11 Sarfraz
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KuwaitKuwaitUniversitUniversit
1. Extract or specify the keyframes.
2. Specify number of in-between frames
between every pair of keyframes.
3. Take each pair of adjacent keyframes asmiddle control points, i.e., Pj and Pj+1 of
Cardinal spline. Take previous and next
keyframes as first and last control points (Pj-1
and Pj+2) respectively.
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8/3/2019 Presentation FIT'11 Sarfraz
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KuwaitKuwaitUniversitUniversit
4. Obtain the motion tweening data by Cardinal
spline interpolation between every pair of
keyframes Pj and Pj+1.
5. If the result is not satisfactory then go to step1, add more keyframes and repeat the
process.
6. Save the keyframes.
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8/3/2019 Presentation FIT'11 Sarfraz
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KuwaitKuwaitUniversitUniversit
Environment of Simulation
Hardware Operating System Prog. Language
Inter Core Duo 2.4
GHz
Linux (Ubuntu 10.04
LTS
MATLAB R2010
Animations used in the Simulation
Animation Name Frame Rate (fps) Number of Frames
Ladder-Climb 30 153
Walk-Turn 24 119
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8/3/2019 Presentation FIT'11 Sarfraz
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KuwaitKuwaitUniversitUniversit
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8/3/2019 Presentation FIT'11 Sarfraz
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KuwaitKuwaitUniversitUniversit
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8/3/2019 Presentation FIT'11 Sarfraz
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KuwaitKuwaitUniversitUniversit
` A simple and efficient method of tweening of
motion data to generate smooth animation
using cubic Cardinal spline.
` The keyframes serve as control points ofCardinal spline to generate in between frames
by interpolation.
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8/3/2019 Presentation FIT'11 Sarfraz
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KuwaitKuwaitUniversitUniversit
Thanks!