CSC2521 Fall 2011:  Topics in Computer Graphics:

Sketching: interaction, modeling and perception.

...stroke processing	...interface control	...gestural drawing	...3D modeling	...curves to surfaces	...stroke perception

Sketch-based interfaces have often been touted as a “natural” approach to interactive design. While sketching is indeed a promising medium of visual communication, there are a number of inherent limitations in the motor control of the human hand, human drawing skill,  perception and  the ambiguities of inference,  that make the leap from  2D sketching to 3D visual concepts a challenging task. This seminar style course will read papers and present results on various aspects of a sketch-based modeling pipeline: gesture drawing, the creation, processing and filtering of strokes to create the metaphor of a virtual 2D sketchbook, an understanding of human limitations in perceiving or drawing accurate 2D projections of imagined 3D shapes,  and finally approaches that facilitate the leap from 2D sketches to 3D models despite these limitations. Students will be exposed to the gamut digital sketching research including techniques to filter strokes, control user interfaces, recognize gestures, create 3D curves and surfaces from 2D sketching and the perception of 3D models projected as 2D sketches.

The course will be co-taught with design students from OCADU DIGF 6B13.

Design students will be paired with CS students for the projects. Design students will present a design perspective and critique on the technical papers presented.

First class: 14 September 2011

Professor

Karan Singh (http://www.dgp.toronto.edu/~karan) U of T

Fanny Chevalier OCADU

Grading scheme

• paper presentation  50%.
• implementation and demo of a small self-contained idea on digital sketching 40% (due by early Dec. 2011). Mid-term evaluation of the project is worth 10 of the 40%.
• project report (1-4 pager) 10% (due by mid Dec. 2011).

Duration

The class will meet once a week W 3-5 in BA 5187, the Dynamic Graphics Project lab (http://www.dgp.toronto.edu).

Schedul

Please also check the latest updates on the course wiki http://sketching.wikispaces.com/

Week #	Slides, reading material	Topics covered
1	Welcome, Introduction	Introduction (KS)
2	What can be sketched, prospective projects	Sketch interface examples, projects (KS)
3	Stroke filter, process, dynamics, gestures	Stroke Filtering, Processing, Gesture Recognition (KS+FC)
4		Sketch-based user interfaces (FC)
5		student paper presentations
6	Case studies	Sketch-based 3D modeling (KS)
7		mid-term review
8		student paper presentations
9	Stroke Perception	Stroke Perception (KS)
10		student paper presentations
11		Sketching and multi-touch (FC)
12		Conclusion (KS) and Final Project Presentations

Links and Papers

• Case Studies:
• SKETCH
• Teddy
• ILoveSketch
• Analytic Drawing of 3D Scaffold
• Stroke depiction NPR: Line Drawings from 3D models SIGGRAPH course notes 2008
• Stroke Perception:
• Why cant most people draw what they see?  Cohen and Bennett 1997
• Where do people draw lines?                       Cole et al. 2008
• How well do line drawings depict shape?    Cole et al. 2009
• Stroke Neatening
• Piece-wise Clothoid curves 2008.
• Kinematic Templates 2008.
• Stroke Processing
• Gestures without Libraries, Toolkits or Training: A $1 Recognizer for User Interface Prototypes
• Modeling human performance of pen stroke gestures.  Cao and Zhai. 2007.Demo Program
• Stroke-based Animation
• Motion Doodles
• As rigid as possible shape manipulation
• Stroke UI
• CrossY
• Sketch Widgets

Starter Code

• Java Applet
• Maya Tool plug-in

Potential Projects

• Facial modeling.
• Drawing scenery and landscapes.
• Production Drawing.
• Flipbooks: sketching for animation.
• Anatomic annotation.
• Physically-based sketching.
• Perception of line drawings (Where is the surface in a line drawing?).
• Ergonomics of sketching curves (Given two points and directions how do we connect them?).

Paper Presentations

--- Week 6 (Oct 26) ---

OverCoat: An Implicit Canvas for 3D Painting

http://zurich.disneyresearch.com/OverCoat/

stephanie santosa

3D Modeling With Silhouettes

http://www.alecrivers.com/3dmodelingwithsilhouettes/

cloud shao

--- Week 9 (Nov 15) ---

Animated Construction of Line Drawings

http://sweb.cityu.edu.hk/hongbofu/projects/animatedConstructionOfLineDrawings_SiggA11/#.Tou3qv7Nltk

chung-lin wen

ShadowDraw: Real-Time User Guidance for Freehand Drawing

https://webspace.utexas.edu/yl3663/~ylee/shadowdraw/shadowdraw.html

rebecca dreezer

Conjoining Gestalt Rules for Abstraction of Architectural Drawings

http://web.siat.ac.cn/~vcc/publications/2011/gestalt_abstraction/

jessica david

--- Week 10 (Nov 22) ---

Sketch-based Dynamic Illustration of Fluid Systems

http://www.designinterface.jp/en/projects/sketchfluid/

alex tessier

2.5D Cartoon Models

http://www.alecrivers.com/2.5dcartoonmodels/

ashish kaila

Sketch-Sketch Revolution: An Engaging Tutorial System for Guided Sketching and Application Learning

http://www.autodeskresearch.com/publications/revolution

jian zhao

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