Far Field Video

Andy Wilson

COMP290-72 Final Presentation

Motivation

• Accelerate massive model rendering by representing distant geometry with simple impostor

• Use MPEG encoding to take advantage of coherence between impostors for adjacent cells

State of the Art

• Massive model rendering: the Walkthrough MMR system

• Video representation: numerous techniques (MPEG1-3, Intel Indeo, H.263, etc.)

• Far-field representations: image-based impostors (TDM, LDI, QTVR, etc.)

Goals

Automatically find paths through a model

Generate video stream from those paths

Allow bidirectional motion through image stream

Integrate video into viewer

Major Setbacks

• Freely available video codecs (with source) are difficult to adapt

• Bidirectional stream navigation requires a lot of work

• Inter-frame dependencies make random access difficult

• Many cryptic parameters in encoder have large effect on quality of output

Sample Loss of Quality

MPEG Normal (PNG)

Future Work

• Better paths through model– more coherence means better images, smaller

streams– Problem known to be NP-complete!

• Bidirectional navigation– Probably requires complete rewrite of MPEG

decoder

• Other representations– panorama, cell-wall movie, ?

Demo: MMR with video images