Brown Computer Graphics Group Brown Computer Graphics Group

Art-based Modeling and Rendering

The proposed new look
for 3D graphics.
standing figure

Project Overview

This project starts from the idea that techniques used by artists and illustrators to communicate visual information can be applied to increase the expressive power of 3D computer graphics. These techniques typically involve an overall reduction of visual detail together with enhancement of the most important details like facial features and object outlines. With careful stylization just a few strokes can be made to evoke a sense of complex geometry like leafy bushes or flowing, glossy hair.

The development of art-based methods for depicting virtual scenes has the potential to bring a wide range of new looks to computer graphics, and also to reduce the cost of modeling complex scenes. If the rendering style evokes the complexity of the scene indirectly, the underlying scene geometry might be relatively simple. One example of a system taking such an approach is described in the Siggraph 99 paper, "Art-based Rendering of Fur, Grass and Trees" (see below).

The main goal of this project is to provide new algorithms and tools with which an artist can apply her skills to define both shapes and the rendering styles used to depict them. As in the children's story, Harold and the Purple Crayon, a user of the system might start out in an empty virtual world and then fill it with complex shapes by drawing them as she moves through the resulting environment.

With that in mind, we seek to build a system in which the user models complex surfaces by first constructing simplified representations of the underlying masses that give them their form. She then "oversketches" the masses with a smooth surface that approximates their collective shape. Two recent papers, "An Interface for Sketching 3D Curves," and "Skin: A Constructive Approach to Modeling Free-form Shapes," address particular sub-problems that arise in carrying out this approach.

The next step will be to generalize the curve-sketching technique and apply it toward an interface for sketching a new class of "soft" primitives. These can be an end in themselves or can serve as "skeletons" over which the user sketches a "skin." We continue to develop new rendering algorithms targeting a wider range of stylized effects, together with user interfaces for customizing these styles and selectively applying them to surface regions.


Lee Markosian
Michael Kowalski
Jonathan M. Cohen
Thomas Crulli
J. D. Northrup
Loring S. Holden
Robert C. Zeleznik
John F. Hughes


Bibtex entries for these papers

Contact:  Lee Markosian

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