ComputerGenerated Graphite Pencil Rendering of 3D Polygonal Models

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Computer-Generated Graphite Pencil Rendering of
3D Polygonal Models

• Mario Costa Sousa and
• John W. Buchanan
• EUROGRAPHICS 99
• University of Alberta, Electronic Arts Centre

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Contents

• Overall Process
• Paper and Pencil Modeling
• Stroke Modeling
• Mark-making Modeling
• Rendering
• Outline and Shading
• Results
• From 3D polygonal model
• From 2D image
• Smudging effects
• Conclusion

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Overall Process
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Pencil and Paper
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Pencil

• Hardness
• From 9H to 8B

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Pencil

• Pencil points
• A polygonal shape

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Pencil

• Pencil points
• Pressure distribution

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Paper

• A texture as a height field Curtis97
• Random
• Digitized from a paper sample

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Scanned Paper

• By a scanning electron microscope(SEM)

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Pencil/Paper Interaction
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Pencil/Paper Interaction

• Depositing lead

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Pencil/Paper Interaction
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Pencil/Paper Interaction
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Pencil/Paper Interaction

• Destroying grains of the paper

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Pencil/Paper Interaction

• Destroying grains of the paper
• Pressure
• Hardness
• Rigidity of paper

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Stroke
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Mark

• A collection of strokes for tone

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Overall Process
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Outline
uniform
accent
sketchy
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Shading
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Tone Value Chart

• Input tone
• Output pencil hardness, number of layer,
  pressure

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Placing Marks
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Drawing Steps
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Results
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Results
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Results

• From 2D images
• Adding smudging effects

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Smudging Effects
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Conclusion

• A system generating a 2D pencil drawing from a 3D
  polygonal model or a 2D image
• For animation ?
• Real-Time Hatching by Praun01