Application of Force-Directed Graphs on Character Positioning

Christine Talbot

Character Positioning

Discovery News – Avatar: Motion Capture Mirrors Emotions

http://news.discovery.com/videos/avatar-making-the-movie/

MindMakers Wiki

http://www.mindmakers.org/

projects/bml-1-0/wiki/Wiki

Spatial Movement (Previous Work)

Sentence

Subject NP

Actor/Noun

VPVP Action/

Verb

NP Target/Noun

Speech Movement

Grouping Spatial Rules

Conversational Spatial Rules

Theatre Rules

General Rules

MindMakers Wiki

http://www.mindmakers.org/

projects/bml-1-0/wiki/Wiki

SmartBody Path Planning

http://smartbody.ict.usc.edu

Adding a Human

Move correctly, on-time

Move correctly, wrong time

Move incorrectly, on-time

Move incorrectly, wrong time

Don’t move at all

Force-Directed Graphs (FDGs)

Equilibrium of Forces

Aesthetically Balanced

Easy to See Nodes

Crossings-Free (some)

Fixed Nodes

Varying Relationships Based on Data

Can be Arranged in Pre-defined Shapes (some)

Force-Directed Graph Samples

WiSo-Nets: Community Detection in Facebook Friends

http://wisonets.wordpress.com/

mbostock’s block #4062045: Character Co-occurrence in Les Miserables

http://bl.ocks.org/mbostock/4062045

Force-Directed Graph Structure

Node Representations: Characters Human Target/Marks/Pawns Audience Central Grouping Point

Linkages Characters – Humans/Characters Characters – Targets/Marks/Pawns Characters – Audience Characters – Central Grouping Point Central Grouping Point - Audience Humans – Central Grouping Point Humans - Audience

A

H

T

AA

Force-Directed Graph Functions

Adding Characters

Characters Leaving

Moving Characters

Human Moves

A

H

T

TA

Forces and Time

What Does it Look Like?

Evaluation Approaches

Optimal arrangement based on current relationships

Time-based / sequential arrangement through entire scene

User evaluation of appropriate positioning

Evaluation CriteriaOptimal arrangement based on current relationships

Even Vertex Distribution Measure character distances

Small Number of Vertices Count number of vertices

Fixed Vertices Measure distance from targets/marks

Centering and Encircling of Groups Comparison to semi-circular shape

Varying Attracting and Repellent Forces Comparison of different forces effects

Results100s of Random Relationship Scenarios

Even Vertex Distribution 3.14 feet (SD=1.54) between characters

Small Number of Vertices At most 40 vertices in graph, with 12 characters

Fixed Vertices 3.30 feet (SD=1.52) from target

Centering and Encircling of Groups Characters formed nice semi-circles

Varying Attracting and Repellent Forces Varied forces for different effects

Summary

Introduced Human-Controlled Character Issues

Proposed Force-Directed Graphs

Provided Algorithms

Implemented Approach

Evaluated First of Three Components

Provided Good Initial Results

Future Work

A

H

T

3.14 feet between chars

Christine Talbot

ctalbot1@uncc.edu

Questions?