Painterly Rendering for Animation

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Painterly Rendering for Animation

• Barbara J. Meier

Walt Disney Feature Animation SIGGRAPH 1996
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Overview

• Previous work
• Main points
• Contributions
• Possible expansions

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Previous Work

• Combines
• Painterly rendering of stills4 Haberli (brush
  strokes)
• Particle rendering10 Reeves (2D coherence)
• Fractal Sketcher3 Zimmer, Hedges, Derry
• Reference images11 Saito
• Animation randomness12 Salisbury

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Algorithm

• Create particles
• For each frame
• Create reference pictures
• Transform particles for animation
• Sort particles by depth
• For each particle render back to front
• Create screen transformation
• Determine brush stroke attributes
• Composite into paint buffer

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Pipeline
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Factors Randomness
With randomness.
Without randomness.
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Factors Brush Attributes

• Image brush texture
• Color reference picture
• Orientation projects 3d normals
• Size frush brush head
• Position particles loc. can get noise

Brush images.
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Effect of Brush Variance
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Effect of Layering

• Render every nth particle
• Shrinks silhouette effects
• Individual objects as well as scene layers
• Provides diverse brush variance

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Contributions

• 1. Image coherence over time (3D particle
  layering)
• 2. Elimination of the shower door effect (obj.
  ref.)
• 3. Rendering styles

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Possible Expansions

• Complex model simplification via abstract style
• Automatic object size changes brush should too
• Evenly distributed particle placement w/o user
• Interactive particle simulation a la snowman