human figure modeling and...
TRANSCRIPT
-
Human Figure Modeling and Animation
-
• Physically based character animation– Human modeled as an articulated body– Ragdoll (for the dead)– Inverse kinematics (for reaching user-specified
goals)
• Data-driven character animation– How to get data?– Motion capture/performance capture– Motion graph (our lab assignment)
Last time…
-
• Modeling– Skinned model– Features: face and hair
• Activities/Motions– upper body tasks: reaching, grasping– locomotion: walking, running
Virtual Human Representation
-
Poser Demo
https://www.youtube.com/watch?v=GLhUKaHzzro�
-
Skinned Human Body
Polygonal representationSkeleton representation
Skinning
-
Review: Skeleton Model
Joint A
Joint B
Joint C
Bone 1
Bone 2
Joint A
Joint B
Joint C
Bone 1
Bone 2
R1X+b1
R2X+b2
Each bone is doing rigid transformation.
-
• Let x be a skin vertex in the original space• We can transform x as the combination of the transformations caused by two bones:
w0(R0x+b0) + w1(R1x+b1)
• W0 and w1 are constant weights.• When there are more bones, there are also more weights…• Demo
Skinning/Rigging
https://www.youtube.com/watch?v=PPbSGUPj72w�
-
Facial animation
Face Modeling
Face animation
Face performance capture
-
Parameterized Facial features
Also see http://www.facegen.com/
http://www.facegen.com/�
-
Facial blend shapes
Another (older) example http://www.youtube.com/watch?v=8dS0dcULRBA
Interpolate between 3D models
http://www.youtube.com/watch?v=8dS0dcULRBA�
-
Real-Time Face Capture
https://www.youtube.com/watch?v=X7y2RZdyZK0�
-
Hair and fur
-
Hair
Complexity100,000 strands
Collisions
Shadowing
Reflections
Design hairstyle
Animate hair
Populate head with hair
Hair types
STRANDS AND HAIRMODELING, ANIMATION, AND RENDERING
SIGGRAPH 2007 Course Notes
http://run.usc.edu/cs599-s10/hair/c33-hair-sig07.pdf�http://run.usc.edu/cs599-s10/hair/c33-hair-sig07.pdf�http://run.usc.edu/cs599-s10/hair/c33-hair-sig07.pdf�
-
• Physically based hair animation– Computationally expensive because of collision– Exact collision handling vs. approximate collision
handling– Simulate a small number of hairs
• The rest hair strands are interpolated– Brave example
Hair Animation and Modeling
https://www.youtube.com/watch?v=Cecx5HVtUDY�
-
• Data-driven hair animation (with styles!)– Hair capture and modeling from videos
– Manipulating the hair in videos directly!
Hair Animation and Modeling
https://www.youtube.com/watch?v=QCgWMIYGbV8�https://www.youtube.com/watch?v=A14UyhABLJ8�
-
Capture facial skin and hair together?
The work done by Disney Research
https://www.youtube.com/watch?v=npecw1ohjA8�
-
Human Body Motion Synthesis
-
• It is impractical to capture every human motion– Hands (due to occlusions)– Swimming?– Accidents?– Too many motions, cannot capture them all
Human Body Motion Synthesis
https://www.youtube.com/watch?v=G8ge9ir3_Sk�https://www.youtube.com/watch?v=VN7Mb0AM6qo�
-
• Sometimes the character is non-human
Human Body Motion Synthesis
http://www.disneyresearch.com/project/animating-non-humanoid-characters-with-human-motion-data/�
Human Figure Modeling �and AnimationLast time…Virtual Human Representation幻灯片编号 4幻灯片编号 5幻灯片编号 6Skinning/Rigging幻灯片编号 8幻灯片编号 9幻灯片编号 10幻灯片编号 11Hair and fur幻灯片编号 13Hair Animation and ModelingHair Animation and ModelingCapture facial skin and hair together?Human Body Motion SynthesisHuman Body Motion SynthesisHuman Body Motion Synthesis