motion capture by: ali hosseini. definition of motion capture motion capture is the recording of...
Post on 22-Dec-2015
231 views
TRANSCRIPT
Motion Capture
By: Ali Hosseini
Definition of Motion Capture
Motion capture is the recording of
human body movement (or other
movement) for immediate or delayed
analysis and playback. “MoCap”
History
• Late 1970’s – Rebecca Allen created the first primitive form of motion capture. “Rotoscoping”
• 1980-1983- Tom Calvert invented “Geniometers”
• 1982-1983- Ginsberg & Maxwell invented “Graphical Marionette”
• 1988- deGraf/Wahrman invented “Mike the Talking Head”
• 1988- Pacific Data Images invented “Waldo C. Graphic”
• 1989- Kleiser- Walczak invented “Dozo”
• 1991- Videosystem invented “Mat the Ghost”
• 1992- SimGraphics invented “Mario”• 1992- Brad deGraph invented
“Alive”• 1993- Acclaim invented two
character animation motion capture
Process of MoCap
• Data needs to be manipulated
• Transform data into file format
• Build specific models
• Attaching the mesh
Questions to Consider
• How many moves in a level?
• Can keyframe techniques be used?
• What process is efficient?
• Budget?
• Knowledge and skill of team?
Preparation Pre-Studio• Spreadsheet breakdown of shots• Diagramming overhead view of action• Story Boards• Floor Plans for desired moves over
large space• Wardrobe, video reference, stunt
support, craft services.
Pre-Shoot List
• Shot list• Move list• Exceptional talent• Food and water
• Talent with comfortable shoes
• A motion capture system and team
• Well rested
Procedure
• Story board drawn up
• Actors positioned at marks
• Director call action
• Operator of MoCap station to start machine
Procedure Cont…
• Game production manager determines best takes.
• MoCap members clean up data• Files are converted into a skeletal
format that is ready for attachment• Skins meet bones
Human Vs. Computer
• MoCap• Quicker Results• Easier to do what
directors wants
• Key framing• Cost effective• Difficult to do what
director wants
Point Weighting & Attachment
• Polygonal characters attached to MoCap data
• Polygonal characters are to be more specific (ex: polygons at elbows, knees, wrist) for maximum flexibility
• Needs to have mesh proportional to bones
• Do attachment right away
Major Problems
• Aggressive moves that need to be stretched and twisted into radical positions tearing and deformation may occur
• Blending Technique stringing all takes
Software Packages for MoCap Data Implementation
• Softimage
• Alias
• 3D Studio Max
3D Studio Max
This software package implements
MoCap data into a PC based Piece of
code
3D Studio Max Plugins
Oxford Metrics • Does well with physique • Has key reduction capabilities to reduce
unwanted data and keep files from balooning
• Allow importation of specified segments of the file and allows moves to blend together with code applied
3D Studio Max Plugins
BioVision
• Called “Motion Manager”
• File format is easy
MoCap Live
Refrences
Sturman, David. “A Brief History of Motion Capture for Computer Character Animation.” 13 March 1999. MEDIALAB. 25 Nov. 2005. http://www.siggraph.org/education/materials/HyperGraph/animation/character_animation
“When Motion Capture Beats Keyframing.” Sept. 1997. Game Developer. http://www.gdmag.com
Kines,Melianthe. “Planning and Directing Motion Capture for Games.” Gecko Interactive.