Interactive Function-based Shape Modeling

Research project started in 1998
Research grant ARP RG1/01,  "Interactive function based shape modeling", 2001-2004

Principal investigator and supervisor: Alexei Sourin
Contributed researchers:
Konstantin Levinski (BSc, MSc, and PhD projects)
Lee Tiong Kuan (BEng project)
Suen Eng Kai (BEng project)

Research grant: NRF IDM grant NRF2008IDM-IDM004-002 "Visual and Haptic Rendering in Co-Space", S$1,248,000,  2008-2011


Last time updated on 28 March, 2010

"Virtual workshop".
Ray tracing, 2000.
Click to enlarge.

Dramatic advances in computer technology have revolutionized the methods and tools of interactive 3D shape modeling where the unique geometric reasoning of the human brain couples with the rapid computing and rendering abilities of the computer. In this project we study interactive function-based shape modeling where relatively small formulae are used rather than thousands of polygons. Interactive modification of the function model with concurrent visualization of the respective part of it  lets us provide both the interactivity and any required level of detail leading to photo-realistic appearance of the resulting shapes.
The modeling is being done with an interactive shape modeling program where the function model of the shape is sequentially modified with offset and set-theoretic operations. The final shape is represented in the data structure as a list of interactive operations over the basic shape. A pressure sensitive graphics tablet and a six degree of freedom haptic input device have been used to realistically simulate the depth of penetration of the tools. For visualization,we have developed special fast interactive ray tracing and  interactive polygonization algorithms. Bounding shapes together with the spatial organization of the function model provide the required fast function evaluation that is usually a bottleneck for function-based shape modeling systems. The software runs on common  PCs. In this page, the artistic application of interactive function-based shape modeling is presented.

Virtual embossing

Embossing is the art of decorating metals. In this technique, the ornament is raised from the back of the metal by means of hammers and punches followed by hammering from the front, which is called chasing. Embossing has been used extensively throughout the history of metalworking. It achieved widespread popularity in Europe during the 16th, 17th, and 18th centuries. One of the places where this art originated from is the Caucasus Mountains.

Tools for embossing.

Tracing the contours.

Bossing up the relief.

The resulted embossing.

Pressure sensitive tablet used in the project.


Tracing the contours.
Virtual embossing, 2000.


Making relief areas
Virtual embossing, 2000


Embossed region.
Virtual embossing, 2000.


"The Jolly Good Dragon"
Copper. 1978

"Girl with a candle".
German silver, 1977.
I embossed it many years ago
Click to enlarge.

Doing virtual embossing with a pressure sensitive graphics tablet.

"Girl with a candle".
Virtual embossing, 2000.
Click to enlarge.

Real embossing, 1999.

"Unruly horses".
Virtual embossing, 2000.
Click to enlarge.

Also, see its 3D model

Virtual embossing, 1999.

compart25.gif (23195 bytes)

Virtual embossing, 2000.
Click to enlarge
Also, see its 3D model

"When the trees were tall"
Virtual embossing, 2001, unfinished

dragon1.GIF (19158 bytes)

dragon4.GIF (14515 bytes)

dragon3.GIF (18697 bytes)

"The Jolly Good Dragon"                Click to enlarge.
Virtual function-based embossing with the fast interactive polygonization, 2001

Virtual carving

Carving  is always done with a cutter, generally by pressure from the hand. It detaches material in cutting.  The same mathematical model with slight modification is used for simulating this art.

Real cutters.

vase2.JPG (6571 bytes)

compart23.gif (30235 bytes)

Virtual carving.
Click at the picture to see the video (100 kbps)
Click here for low-speed connection.


"Moscow nights"
Virtual wooden board cut, 2001.
Click to enlarge.


Real wooden board cut.
Compare with its virtual version on the right.

Virtual wooden board cut, 2000.
Click to enlarge.

vase_r.GIF (12937 bytes)

A virtual crystal vase
Click to enlarge.


vase_o.GIF (16901 bytes)

The original vase which inspired us
to make it with a computer

Virtual sculpting and painting

Candlestick, 2004
Made with a new version of the interactive shape modeling program. CW2004
Mouth of Truth, 2004
Made with a new version of the interactive shape modeling program. CW2004

Visit also Function-based extension of VRML
All of the 3D models will be made available for viewing there through the FShape plug-in for VRML.

Selected Publications

K.Levinski and A.Sourin. Interactive Function-Based Shape Modelling, Computers & Graphics, Elsevier, 2007;31(1):66-76.

A.Chong, K.Levinski and A.Sourin. Interactive Grid-based Free-Form Shape Modeling. IEEE CCGrid, 253-256, 2006

Alexei Sourin, Computer Graphics. From a Small Formula to Cyberworlds, Prentice Hall, Singapore, ISBN 9810675518, 362 pages, 2005.

K.Levinski and A.Sourin, Interactive Function-Based Shape Modeling for Cyberworlds, 2004 International Conference on Cyberworlds, Tokyo, 18-20 November, 2004, pp.54-61.

K.Levinski and A.Sourin, "Interactive function-based artistic shape modeling", 2002 International Symposium Cyber Worlds: Theory and Practice 2002, Tokyo, Japan 6-8 November, 2002 pp.521-528.

 K.Levinski and A.Sourin, "Interactive polygonisation for function-based shape modelling", Eurographics 2002, Short Presentations, ISSN 1017-4565, pp.71-79, 2002. 

A.Sourin, "Functionally based virtual computer art", The 2001 ACM Symposium on Interactive Computer Graphics, I3D2001, Research Triangle Park, NC, USA, 19-21, March, 2001, ACM ISBN: 1-58113-292-1, pp.77-84. 

A.Sourin,"Functionally based virtual embossing",The Visual Computer, 17 (2001), 4, pp.258-271.

  Function Representation (FRep)

Copyright 1996-2006 Alexei Sourin.
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