Hand-painted Animation with Intelligent Brushes

Tom Van Laerhoven, Fabian Di Fiore & Frank Van Reeth{firstname.lastname}@uhasselt.be

Hasselt University - Expertise Centre for Digital Mediatransnationale Universiteit Limburg

Belgium

CASA’08

CASA’08 Sep 1th - Sep 3th Tom Van Laerhoven

Goals

CASA’08 Sep 1th - Sep 3th Tom Van Laerhoven

• Enrich interactively created stylized images with procedural animation.

• Make animation techniques available to untrained users.

• Avoid steep learning process.

Approach

CASA’08 Sep 1th - Sep 3th Tom Van Laerhoven

• Physically-inspired interactive painting tool “AquaVerve”.

• Animated canvas with separate canvasfor each frame.

• Special-purpose “intelligent” brushes.

• Animated pigment.• Show animation continuously.

Background

CASA’08 Sep 1th - Sep 3th Tom Van Laerhoven

• Commercial packages: Corel Painter, MoXi, ArtRage, Project Dogwaffle• ‘Only’ provide digital equivalent of traditional painting.

• Literature

I/O Brush[Ryokai et al. CHI04]

Easel [Rozin 98]

Paint-Cam [Rozin 98]

AntBrush[Tzafestas 00]

AquaVerve

CASA’08 Sep 1th - Sep 3th Tom Van Laerhoven

• Interactive paint system• Watercolour, gouache, impasto, …• Physically & empirically-

based paint algorithms, GPU impl.[Van Laerhoven et al. CASA05]

• Virtual brush design [Van Laerhoven CGI07]

Animated Canvas

CASA’08 Sep 1th - Sep 3th Tom Van Laerhoven

• Set of 8 – 16 canvasses.• Animation is shown continuously.• Need for specialized brushes.

canvas representation1024x768 simulation grid

Intelligent Brushes

CASA’08 Sep 1th - Sep 3th Tom Van Laerhoven

• Semi-autonomous brush: flame brush

User: Interactively paint stroke

System:Record:• brush reservoir• stroke trajectory• brush attributes

Intelligent Brushes

CASA’08 Sep 1th - Sep 3th Tom Van Laerhoven

• Semi-autonomous brush: flame brush

…

User: Interactively paint stroke

Automatically-drawn scripted variations

frame 0 frame 1 frame N

System:Record:• brush reservoir• stroke trajectory• brush attributes

…

undo

Intelligent Brushes

CASA’08 Sep 1th - Sep 3th Tom Van Laerhoven

• Semi-autonomous brush: flame brush

…

User: Interactively paint stroke

Automatically-drawn scripted variations

frame 0 frame 1 frame N

System:Record:• brush reservoir• stroke trajectory• brush attributes

…

undo

Intelligent Brushes

CASA’08 Sep 1th - Sep 3th Tom Van Laerhoven

• Moving-dab brush• Paint dabs on

successive frames

Intelligent Brushes

CASA’08 Sep 1th - Sep 3th Tom Van Laerhoven

• Steady brush• Paint on all frames at once• Erase animated strokes

Painting motionless background Erasing animation

Animated Pigment

CASA’08 Sep 1th - Sep 3th Tom Van Laerhoven

• Secondary motion• E.g., animate the observed thickness of a single

pigment type in impasto paint layer• Vibrant or waving paint textures

Single-out a pigment type in a mix

Pigment properties:• stickiness• clumping• weight• animation

Results

CASA’08 Sep 1th - Sep 3th Tom Van Laerhoven

• Camp fire• Semi-autonomous flame

brush• Primary flames• Smoke trail

• Moving-dab brush• Secondary flames

• Steady brush• Background

• Yellow pigment withvibrant flame-like motion

Results

CASA’08 Sep 1th - Sep 3th Tom Van Laerhoven

• Flowing water• Semi-autonomous water brush• Blue pigment that exhibits soft waving motion

Conclusions & Future Work

CASA’08 Sep 1th - Sep 3th Tom Van Laerhoven

• Brushes & pigment enhanced with behavioral intelligence

• Enrich & animate interactively created images• Within reach of every digital painter

• Future work• Animation of stroke textures• Extend intelligent brush set; more complex

scripts

Thank You

Questions?

http://research.edm.uhasselt.be/tvanlaerhoven

CASA’08 Sep 1th - Sep 3th Tom Van Laerhoven