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Relief: A Modeling by Drawing Tool David Bourguignon 1 Raphalle Chaine 2 Marie-Paule Cani 3 George Drettakis 4 1 Princeton University / INRIA Rocquencourt 2 LIRIS / CNRS / UCBL 3 GRAVIR / INP Grenoble 4 REVES / INRIA Sophia-Antipolis Slide 2 Outline Motivation Previous Work Tool Workflow Reconstruction Adaptive Sampling & Depth Inference Tool Interface Results Slide 3 On Users Most people draw Writing alternative Few people sculpt Play-Doh days long gone Materials difficult to handle Slide 4 Goals Use 2D tools to perform 3D operations Slide 5 Goals Use 2D tools to perform 3D operations Model global and local surface Slide 6 Goals Use 2D tools to perform 3D operations Model global and local surface Input: just plain strokes Slide 7 Goals Use 2D tools to perform 3D operations Model global and local surface Input: just plain strokes Output: triangle mesh Slide 8 Outline Motivations Previous Work Tool Workflow Reconstruction Adaptive Sampling & Depth Inference Tool Interface Results Slide 9 Previous Work Depth painting [Williams, 1990] + Slide 10 Previous Work Gradient editing [van Overveld, 1996] Slide 11 Previous Work Maya 6.0 Artisan [Alias, 2004] Slide 12 Outline Motivations Previous Work Tool Workflow Reconstruction Adaptive Sampling & Depth Inference Tool Interface Results Slide 13 Tool Workflow First step: drawing input Displacement map mid-grey = 0 white > 0 black < 0 Model of 3D sphere Pencil Brush Slide 14 Tool Workflow First step: drawing Displacement map 2D shape boundary (in green) defines drawing mask Slide 15 Tool Workflow First step: drawing Displacement map 2D shape boundary Displacement regions (from 2 maps) Slide 16 Tool Workflow Second step: modeling Displace existing vertices Slide 17 Tool Workflow Second step: modeling Displace existing vertices Create new surface patch Slide 18 Tool Workflow Changing viewpoint Modeling by drawing Changing viewpoint Slide 19 Reconstruction Based on evolving pseudo-manifold [Chaine, 2003] Slide 20 Reconstruction Based on evolving pseudo-manifold [Chaine, 2003] Satisfy our requirements Arbitrary number of connected components Slide 21 Reconstruction Based on evolving pseudo-manifold [Chaine, 2003] Satisfy our requirements Arbitrary number of connected components Handle points off shape boundary Slide 22 Reconstruction Based on evolving pseudo-manifold [Chaine, 2003] Satisfy our requirements Arbitrary number of connected components Handle points off shape boundary Interactive (5k points per second) Slide 23 2D reconstruction Start: pseudo-curve lies on oriented edges of Delaunay triangulation Slide 24 2D reconstruction During: pseudo-curve evolves as long as oriented Gabriel criterion is not met Slide 25 2D reconstruction Stop: topologically consistent set of oriented edges Slide 26 Sampling and Depth Adaptive sampling Displacement map Pencil and brush data in color buffer Color buffer Slide 27 Sampling and Depth Adaptive sampling Displacement map Approximate disp. map sampled at existing vertices Slide 28 Sampling and Depth Adaptive sampling Displacement map (D) Vertex-Sampled disp. map (V) Error map E = 1 ABS(D V) Arbitrary error value Slide 29 Sampling and Depth Adaptive sampling Displacement map Approximate disp. map Error map Sampling [Alliez, 2002] Slide 30 Sampling and Depth Adaptive sampling Depth inference Identify surface vertices Vertices ID buffer Slide 31 Sampling and Depth Adaptive sampling Depth inference Identify surface vertices Assign depth values Depth buffer Slide 32 Sampling and Depth Adaptive sampling Depth inference Identify surface vertices Assign depth values Infer depth values from existing surface by depth propagation Slide 33 Outline Motivations Previous Work Tool Workflow Reconstruction Adaptive Sampling & Depth Inference Tool Interface Results Slide 34 Tool Interface Hole marks Comic books production Hole marks Stone #3 (Avalon Studios) Slide 35 Tool Interface Hole marks Comic books production Our system Hole mark Slide 36 Tool Interface Video: Basic interface Slide 37 Tool Interface Blobbing DrawingWhite shadingDistance fieldHeight fieldSurface Slide 38 Tool Interface Depth modes (chosen by menu) Modeling at depthDepth inferenceFrisket mode Slide 39 Video Modeling a tree Paper sketch3D model obtained with Relief Slide 40 Outline Motivations Previous Work Tool Workflow Reconstruction Adaptive Sampling & Depth Inference Tool Interface Results Slide 41 Models (1k to 4k points) Slide 42 Discussion Intuitive shading convention Slide 43 Discussion Intuitive shading convention Problems with drawing metaphor No continuous visual feedback Provide two modes Slide 44 Discussion Intuitive shading convention Problems with drawing metaphor No continuous visual feedback Difficult to obtain continuous shading Provide higher-level drawing tools Slide 45 Conclusion Modeling by drawing, but imprecise Slide 46 Conclusion Modeling by drawing, but imprecise Future work Speedup with local 3D reconstruction Slide 47 Conclusion Modeling by drawing, but imprecise Future work Speedup with local 3D reconstruction Improve depth inference Slide 48 Conclusion Modeling by drawing, but imprecise Future work Speedup with local 3D reconstruction Improve depth inference Image-space and object-space sampling Slide 49 Acknowledgements This work has been performed while the first author was a visiting research fellow at Princeton University, supported by an INRIA post-doctoral fellowship. Many people have indirectly contributed to it. We would like to thank: Adam Finkelstein, Szymon Rusinkiewicz, Jason Lawrence, Pierre Alliez, Mariette Yvinec, Laurence Boissieux, Laure Hegas, Laks Raghupathi, Olivier Cuisenaire, Bingfeng Zhou. Slide 50 Slide 51 Slide 52 Reconstruction Input: shape from strokes 2D reconstruction 3D reconstruction Slide 53 Problems to be solved Provide appropriate drawing rep. Shape from strokes Slide 54 Tool Workflow Second step: modeling Adaptive sampling Slide 55 Tool Workflow Second step: modeling Adaptive sampling Depth inference Slide 56 Our Approach Provide appropriate drawing rep. Shape from strokes Displacement from shading White/black metaphor for displacement Rafaello Sanzio Slide 57 Our Approach Provide appropriate drawing rep. Provide appropriate surface rep. Free-form appearance Slide 58 Our Approach Provide appropriate drawing rep. 2D Shape from strokes Slide 59 Our Approach Provide appropriate drawing rep. Provide appropriate surface rep. Free-form appearance Arbitrary topology changes Slide 60 Outline Motivations Previous Work Contributions Results Slide 61 Contributions Overview Curve and surface reconstruction Slide 62 Contributions Overview Curve and surface reconstruction Adaptive sampling and depth inference Slide 63 Contributions Overview Curve and surface reconstruction Adaptive sampling and depth inference Modeling by drawing interface Slide 64 On Users Most people draw Writing alternative Slide 65 On Users Most people draw Writing alternative Minimal tool set Slide 66 On Users Most people draw Writing alternative Minimal tool set Since kindergarten Slide 67 On Users Most people draw Few people sculpt Play-Doh days long gone Slide 68 Previous Work Wireframe reconstruction [Lipson, 1996] Slide 69 Previous Work Gesture-based interfaces [Zeleznik, 1996][Igarashi, 1999] Slide 70 Conclusion Modeling by drawing, but imprecise Future work Speedup with local 3D reconstruction Modeling alternative for thin parts CurrentAlternativeThin parts