Computer Animation Representing changing (animated) objects in a - - PowerPoint PPT Presentation

CSE6335 Topics in Virtual Reality

Wednesday March 30, 2009

Computer Animation

Representing changing (animated) objects in a virtual environment. Requires high performance (low latency) ability to animate a range of different types of events

Basic animation types

Key frame Parametric key frame Tracked Physics-based Behavior-based (flock)

Key Frame

Hand draw (compute) frames at discrete times. Interpolate required frame between key frames. The problem is that ‘guessing’ the missing frames can be very difficult without knowledge of the underlying structure of the world.

Parametric Key Frame

Key frame animation but with the intermediate frames generated based on a parametric model of the scene. Forces the intermediate frames to behave ‘rationally’.

Tracked

Track features and drive the animation from the tracked data. Used for tracking the user Can also be used to generate data for other moving entities in the environment.

H-ANIM

Accepted mechanism for modelling human body h-anim.org Define a set of joints and rigid connections Modeling human -> computing joint angles and COG as a function of time.

Active visual tracking

VICON System markers on an actor track using special cameras recover 3d motion as a function of time

Point Tracking

Magnetic tracking transmitter generates a magnetic field Receiver obtains signals to compute (x,y,z,p,q,r).

Physics-based animation

There exists some physics model that makes ‘physics’ work. Objects are given mass/inertia Input is the application of forces to the world