1. Application to Animating a Digital Actor on Flat Terrain
Joint variables are avars for primary motions.
A Motion clip is a curve parameterized by time in the joint space (C-space).
MPEG4-SNHC standard body description
each hand = 25 DOF
lower body = 21
upper body = 62
global hip position & orientation = 6
The actor The environment

2. Principle: Bound the actor by a cylinder and project all objects the ground
Joint variables are avars for primary motions.
A Motion clip is a curve parameterized by time in the joint space (C-space).
MPEG4-SNHC standard body description
each hand = 25 DOF
lower body = 21
upper body = 62
global hip position & orientation = 6

4. Shrink the disc representing the actor to a point and grow the obstacles accordingly

6. How would you adapt the visibility graph method?

7. Motion Capture

10. Integration of Motion Planning and Motion Capture
High-Level
Navigation Goals
Fast 2D
Path Planner
Path
Consider the problem of controlling an animated character instructed to navigate towards a goal location on a level-terrain cluttered with obstacles
Path-Following Controller
Body
Posture
Graphic
Display
Base Point
PD Controller
Motion
Capture Data

12. Extensions? Small obstacle Soft, but uniform terrain Gap in terrain
Stairs
...
Rough, irregular, possibly steep terrain

13. Simulated Vision Actor’s view
KEY CONCEPT: Realistically model the information flow from the environment to the character.
Complete access to all objects is both conceptually unrealistic and can be impractical for large environments
Tasks involving navigation and obstacle avoidance require visual feedback
Problem: Need to compute what objects are currently visible to an animated agent (3D visibility query).
PREVIOUS WORK:
Spherical sensors (C. Reynolds, ‘87)
Ray-casting techniques (Tu & Terzopoulos ‘94/ C. Reynolds ‘91/ Funge, et al. ‘97)
False-color Rendering and dynamic octrees (Noser, et al. ‘92)
Iterative pattern-matching and color histograms (Terzopoulos & Rabie ‘96)
Image-based motion energy (B. Blumberg ‘96)
Actor’s view

14. Perception-Based Planning
GOAL: Allow a character to explore an unknown interactive virtual environment.
Character should maintain a visual memory or “cognitive map” of what it has perceived through the synthetic vision module.
This map can subsequently be used as input to a navigation planner.
The visual memory data structure must be simple and efficient to access and update.
The navigation plan is updated as the character explores the environment
Fast
Path
Planner
Path-Following Controller
Base Point
PD Controller
Motion
Capture Data
Simulated
Vision
Obstacles

15. Perception-Based Planning
GOAL: Allow a character to explore an unknown interactive virtual environment.
Character should maintain a visual memory or “cognitive map” of what it has perceived through the synthetic vision module.
This map can subsequently be used as input to a navigation planner.
The visual memory data structure must be simple and efficient to access and update.
The navigation plan is updated as the character explores the environment
Plan
Sense
Act

17. Actor that remembers and learns
Should a digital actor remember the objects it sees and their locations?
How could it detect that the environment has changed between two visits?
What could it learn about objects?