Expressing Rendering for Interactive Applications Recent results - - PowerPoint PPT Presentation
Expressing Rendering for Interactive Applications Recent results from two INRIA projects AERIS IPARLA A. Bousseau P. Barla J. Thollot X. Granier D. Vanderhaeghe R. Vergne (INRIA Grenoble) (INRIA Bordeaux) Expressive Rendering for
– Known as NPR (Non-Photorealistic Rendering) – Focus on user control and expressivity – Well adapted to video game industry.
– AERIS in Grenoble – IPARLA in Bordeaux
– INRIA Rhône-Alpes
– Computer graphics – rendering – Previously known as ARTIS
– Computer graphics - 3D interaction / mobility – INRIA Bordeaux Sud-Ouest (01/01/2008)
– Color quantization – Static paper effects – Line drawing techniques
– X-Toon – Dynamic canvas / Watercolorization – Dynamic drawing patterns / Shaded line drawings
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N . L Simple shading
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N . L Toon shading
– Extremely simple to implement – Very fast in both software and hardware – Fully compatible with any lighting system
– Only one control: the 1D texture – Only based on the illumination (1D parameter) – No paper or medium effect
– Looks like a wallpaper rather than a canvas property
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– Looks like a wallpaper rather than a canvas property
– Using texture sequences: no temporal coherence – Using a static texture: sliding, or shower door effect
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– Object space: N.V 0 – Image space: Z discontinuities
– Object space: curvature extrema – Image space: Normal discontinuities
– Object and image space approaches – Can be combined to get more lines
– Usually rendered directly, with no style – Patterns like hatching usually absent – Only geometric properties
– Using 2D textures – First dimension:
– Second dimension:
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– grain / folding / ... – without shower door effect – with temporal coherence
– convert 3D to 2D
– infinite zoom
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– non-uniform pigment density – edge darkening and wobbling – brush effects
– canvas and paper grain – water repartition – pigment flow and density – brush
Quantization Abstraction
Wobbling Quantization Abstraction
Quantization Wobbling Contours Abstraction
– convert 3D movement of object in 2D movements – multiple textures attached to particles
– infinite zoom on each texture
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Quantization Wobbling Contours Abstraction medium
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– expressivity of X-Toon – pigment / turbulence / paper choice
– new approach for a Maya plugin Graphanim – pending patent
– abstraction using 2D + time segmentation – temporal coherence using optical flow http://www.studio-broceliande.com/
– Uniform in 2D space – No surface parametrization
– Subdivide into patches – Attach particles to the mesh – 3D to 2D local conversion – Blending between the patches
http://code.google.com/p/jot-lib/
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– Preserving characteristic features – Style independancy
– Lighting adjustment – Modification of light direction (exaggerated shading) – Extraction of lines
Objet 3D original Information map (curvature) (curvature direction) X-Toon Rendering Processing, image space (2D) Information extraction
Ridges X-Toon black & white Exaggerated Lines Color adjustment Light adjustment X-Toon textures
– 3D to 2D movement conversion (particles) – preservation of a uniform density
– 3D to 2D movement conversion (particles) – preservation of a uniform density
– Similar to texture synthesis – Using vectorial information
Clustering Line creation
– Patterns / paper / pigment / .... – Temporal coherency
– X-toon / dynamic pattern / watercolor / painterly – User controls – Expressivity – Interactive
– New research directions due to new problems
– Direct partenership – National fundings (ANVAR, ANR, ....) – Consulting – PhD students or internships
– Pascal Barla
– Xavier Granier
– Joëlle Thollot
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Dynamic Canvas for Non-Photorealistic Walktroughs [Cunzi et al. 2003]
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Geometric Clustering for Line Drawing Simplification [Barla et al. 2005]
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Stroke Pattern Analysis and Synthesis [Barla et al. 2005]
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Interactive Watercolor Rendering with Temporal Coherence and Abstraction [Bousseau et al. 2006]
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X-Toon: An extended toon shader [Barla et al. 2006]
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Dynamic 2D Patterns for Shading 3D Scenes [Breslav et al. 2007]
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Dynamic point distribution for stroke-based rendering [Vanderhaeghe et al. 2007]
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Video Watercolorization using Bidirectional Texture Advection [Vanderhaeghe et al. 2007]
– painterly rendering – line simplification – information map – watercolor for videos
– Illumination laws are not the only rules
– Classical styles
– New styles
– Shape / Materials – Illumination
– User controls – Legibility – Depiction [Durand 2002]
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