1cs426-winter-2008 Notes  Text: End of 7.8 discusses flocking 7.13 discusses skinning 7.10 discusses motion capture  Remember online course evaluations

2cs426-winter-2008 Move trees  Standard videogame solution  Design a graph corresponding to available player actions E.g. walk forward, turn, jump, …  Design and record corresponding actions with mocap  Warp/retime/edit to make clips smoothly transition where needed  Note: in playback need to keep separate track of global position/orientation

3cs426-winter-2008 Motion Graphs  Recently, people have started constructing “move trees” automatically from long streams of mocap data  Assignment 3, and some other papers from the same year Lee, Chai, Reitsma, Hodgins, Pollard, “Interactive Control of Avatars Animated with Human Motion Data”, SIGGRAPH 2002 Arikan, Forsyth, “Interactive Motion Generation from Examples”, SIGGRAPH 2002  Goal is to chop a long stream into reusable samples, allow for remixing

4cs426-winter-2008 Building a motion graph  First need to look for good transition frames: A frame in the data which resembles other frames Pose (ignoring global position/orientation) is similar Velocity/acceleration is similar  Chop up stream between these points, add connections  Prune graph, warp/clean up clips  Keep track of constraints (footskate!)

5cs426-winter-2008 Using a motion graph  If you make a very high quality graph, use just like a move tree Gleicher et al., “Snap Together Motion…” I3D 2003  Otherwise, graph might be too large and irregular for human to make sense of Planning problem

6cs426-winter-2008 Future uses  Mocap data limited by what was recorded Motion warping, interpolation between motions, can’t extend too far  Classic videogame problem: running football player gets tackled  Research goal: use mocap data as example data for machine learning of human-like controller  See Michiel van de Panne’s web-page for work along these lines