Research

Material and Texture Models
Recovering Shape and Reflectance
Sketching and Alternative Design Techniques
Modeling and Interacting with Architectural Scale Scenes
Applications of Perception to Computer Graphics
Applications of Computer Graphics in Cultural Heritage

Material and Texture Models
 

While researchers have made great strides in light transport algorithms, or rendering, simulations depend just as much on the underlying material models. Unfortunately, the models widely used in computer graphics assume that the materials are both pristine and immutable, even though real materials are neither. One of the central goals of our research is to devise both new material representations and operators for generating and capturing a broad range of complex surface appearances. By incorporating additional information about a material's structure, its interaction with light, and the physical processes that affect it, we are able to simulate a range of complex appearances that would be difficult---if not impossible---to achieve with traditional techniques. We are developing methods both to simulate materials and the processes that affect them, and to physically measure the input required for these models.

Related Publications

Context-Aware Textures. Jianye Lu, Athinodoros S. Georghiades, Andreas Glaser, Hongzhi Wu, Li-Yi Wei, Baining Guo, Julie Dorsey, and Holly Rushmeier. To appear in January issue of ACM Transactions on Graphics, 2007. [webpage] [video] [source data]

Synthesis of material drying history: phenonmenon modeling, transferring and rendering. Jianye Lu, Athinodoros S. Georghiades, Holly Rushmeier, Julie Dorsey and Chen Xu. Eurographics Workshop on Natural Phenomena, August 2005. [video1, video2]

Observing and transferring material histories. Athinodoros S. Georghiades, Jianye Lu, Chen Xu, Julie Dorsey and Holly Rushmeier. YALEU/DCS/TR-1329, June 2005.

Real-Time Rendering of Plant Leaves Lifeng. Wang, Wenle Wang, Julie Dorsey, Xu Yang, Baining Guo, and Heung-Yeung Shum ACM SIGGRAPH 2005. [video]

Stereological Techniques for Solid Textures. Robert Jagnow, Julie Dorsey, and Holly Rushmeier, Proceedings of SIGGRAPH 2004, Los Angeles, CA.

Digital materials and virtual weathering.  J. Dorsey and P. Hanrahan.  Scientific American, Vol. 282(2): 46-53, February 2000. [Introduction on Scientific American]

Modeling and rendering of weathered stone.  J. Dorsey, A. Edelman, H. Jensen, J. Legakis, and H. Pedersen.  Proceedings of SIGGRAPH 1999, in Computer Graphics Proceedings, Annual Conference Series, 225-234, August 1999.

Flow and changes in appearance.  J. Dorsey, H. K. Pedersen and P. Hanrahan.  Proceedings of SIGGRAPH 1996, in Computer Graphics Proceedings, Annual Conference Series, 411-420, August 1996.

Modeling and rendering of metallic patinas.  J. Dorsey and P. Hanrahan.  Proceedings of SIGGRAPH 1996, in Computer Graphics Proceedings, Annual Conference Series, 387-396, August 1996.

Recovering Shape and Reflectance
 

We are studying a variety of improved methods for capturing the shape and appearance of objects.

Related Publications

Using Digital Images to Reconstruct 3D Biological Forms: A New Tool for Morphological Studies. Ylenia Chiari, Bing Wnag, Holly Rushmeier, and Adalgisa Caccone. Biological Journal of the Linnean Society, to appear.

A System for Reconstructing Integrated Texture Maps for Large Structures. Chen Xu, Athinodoros Georghiades, Holly Rushmeier and Julie Dorsey, 3rd Int. Symp. on 3-D Data Processing, Visualization and Transmission, Chapel Hill, North Carolina, June 2006. NOTE: Data used in this paper is available.

Image Guided Geometry Inference. Songhua Xu, Athinodoros Georghiades, Holly Rushmeier, Julie Dorsey and Leonard McMillan, 3rd Int. Symp. on 3-D Data Processing, Visualization and Transmission, Chapel Hill, North Carolina, June 2006.

3D Reconstruction by Shadow Carving: Theory and Practical Evaluation, Savarese, S., M. Andreeto, H. Rushmeier, F. Bernardini and P. Perona , International Journal of Computer Vision, 2006, in press.

Incorporating the Torrance and Sparrow Model of Reflectance in Uncalibrated Photometric Stereo. Athinodoros S. Georghiades. Int. Conf. on Computer Vision, October 2003, pp. 816-823.

Recovering 3-D Shape and Reflectance From a Small Number of Photographs. Athinodoros S. Georghiades, Eurographics Symposium on Rendering, June 2003, pp. 230-240, 315.

Sketching and Alternative Design Techniques
 

Computer graphics plays a major role in the architecture profession.  For example, modeling and rendering systems have proven to be invaluable aids in the visualization process, allowing designers to walk through their designs with photorealistic imagery.  However, computer graphics techniques are typically employed at the conclusion of the design process.  In fact, most of the artistic and intellectual challenges of an architectural design have already been resolved by the time a designer sits down in front of a computer. We recently introduced a sketching paradigm that is aimed at the early stages of design.  Our approach utilizes a projective representation of points, i.e. points that lie on the surface of a unit sphere centered at the viewpoint.  This representation offers the advantage of not having to disambiguate and dimension a 3D model, and it is significant because it allows pseudo-3D interaction with a 2D model created with the ease of pencil sketching.  We are currently developing a sketch-based modeling system that facilitates an easy back-and-forth between 2-D and 3-D representations as well as interaction with a novel combined representation.

Related Publications

The Mental Canvas: A Tool for Conceptual Architectural Design and Analysis. Dorsey, J., Xu, S., Smedresman, G., Rushmeier, H., and McMillan, L. To appear in Proceedings of Pacific Graphics, October, 2007.

Image-Based Object Editing. Rushmeier, H., J. Gomes, L. Balmelli, F. Bernardini and G. Taubin, 4th International Conference on 3D Digital Imaging and Modeling (3DIM '03) Banff, Alberta , October 2003.

A projective drawing system. O. Tolba, J. Dorsey, and L. McMillan. Proceedings of the 2001 ACM Symposium on Interactive 3D Graphics (Research Triangle Park, NC), pages 25-34, March 2001.

Image-based modeling and photo editing.  B. M. Oh, M. Chen, J. Dorsey, and F. Durand.  Proceedings of SIGGRAPH 2001, in Computer Graphics Proceedings, Annual Conference Series, 433-442, August 2001.

Modeling and Interacting with Architectural Scale Scenes
 

With the proliferation of 3D graphics capabilities and the introduction of virtual reality systems, an increasing number of applications are being developed that require the interactive visualization of complex 3D scenes. However impressive the evolution of graphics hardware has been over the past thirty years, the goal of realistically modeling and interactively manipulating scenes of industrial complexity remains an elusive one. We are developing improved methods for the capture and editing of architectural-scale models with a mix of 3D scanning, digital photography, and novel user interfaces. We are developing new algorithms to accelerate the visualization of very complex 3D scenes using novel simplification techniques and image-based impostors, which can supplant complex geometrical objects. Our initial focus concerns the modeling of and interactive navigation in urban environments, and our testbed is the Yale Campus.

Related Publications

Billboard Clouds for Extreme Model Simplification. X. Decoret, F. Durand, F. Sillion, and J. Dorsey, ACM SIGGRAPH 2003.

The 3D Model Acquisition Pipeline F. Bernardini, and H. Rushmeier, Computer Graphics Forum, Vol. 21, No. 2, 2002.

Feature-based cellular texturing for architectural models  J. Legakis, J. Dorsey, and S. Gortler.  Proceedings of SIGGRAPH 2001, in Computer Graphics Proceedings, Annual Conference Series, 309-316, August 2001.

Reconstructing 3D tree models from instrumented photographs.  I. Shlyakhter, M. Rozenoer, J. Dorsey, and S. Teller.  IEEE Computer Graphics and Applications, 21(3): 53-61, May/June 2001.

Conservative volumetric visibility with occluder fusion.  G. Schaufler, J. Dorsey, X. Decoret, and F. Sillion.  Proceedings of SIGGRAPH 2000, in Computer Graphics Proceedings, Annual Conference Series, 229-238, July 2000.

Multi-layered impostors for accelerated rendering.  X. Decoret, G. Schaufler, F. Sillion, and J. Dorsey.  Computer Graphics Forum, 18(3): 61-73, September 1999.  Presented at Eurographics ’99.

Applications of Perception to Computer Graphics
 

We generate synthetic computer images for people. By exploiting properties of the human visual system we can generate images more efficiently, and more effectively. In the past we have applied principles of perception to the tone mapping problem for displaying high dynamic range images on limited devices. Insights into perception may also produce more efficient techniques for texture synthesis and geometric representation.

Related Publications

The Perception of Simulated Materials.  Holly Rushmeier. Proceedings of Human Vision and Electronic Imaging XIII, San Jose, CA, January 2008.

Evaluation of Methods for Approximating Shapes Used to Synthesize 3D Solid Textures.  Robert Jagnow, Julie Dorsey, and Holly Rushmeier. ACM Transactions on Applied Perception, vol 4, no 4, January 2008.

Fast bilateral filtering for the display of high-dynamic range images.  F. Durand and J. Dorsey. In Proceedings of SIGGRAPH 2002, in Computer Graphics Proceedings, Annual Conference Series, July 2002.

Interactive tone mapping.  F. Durand and J. Dorsey.  In D. Lischinski and G. W. Larson, editors, Rendering Techniques ’00, pages 219-230, Springer-Verlag, 2000. Presented at the Eleventh Eurographics Workshop on Rendering (Brno, Czech Republic), June 2000.

Perceptual issues in substituting texture for geometry. H.E. Rushmeier, B.E. Rogowitz, C. Piatko, Proceedings of SPIE Vol. 3959 Human Vision and Electronic Imaging V, 372-383, (2000)

A Visibility Matching Tone Reproduction Opera tor for High Dynamic Range  Scenes. Larson, Greg, Holly Rushmeier and Christine Piatko, IEEE Transactions on Visualization and Computer Graphics, October-December 1997, Vol. 3, No. 4, pp. 291-306.

Applications in Cultural Heritage
 

Over the past decade information technology has been applied increasingly in both studying and communicating cultural heritage. In past projects we have used a combination of shape capture from computer vision and image synthesis computer graphics to study the structure and history of a particular sculpture, and to prepare materials for presenting museum artifacts over the Internet.  We are continuing to develop methods for measuring and analyzing artifacts for expert use, as well more effective methods for the visual communication of heritage for the general public.

Related Publications

Shape Capture Assisted by Traditional Tools. Holly Rushmeier, Chen Xu, Bing Wang, Russell Rushmeier, Julie Dorsey. Proceedings of the 8th International Symposium on Virtual Reality, Archaeology and Intelligent Cultural Heritage 2007, Brighton, UK. [video]

Engineering Methods for Digital Restoration Applications. Ioana Boier-Martin and Holly Rushmeier. Journal of Computing And Information Science In Engineering, in press 2006.

Eternal Egypt:experiences and research directions. H. Rushmeier, International Workshop on Recording, Modeling and Visualization of Cultural Heritage, May 22-27, 2005, Ascona, Switzerland, Balkema publishers.

The Development of the Virtual Model of Michelangelo's Florence Pieta`. Bernardini, F. , H. Rushmeier, I. Martin, J. Mittleman and G. Taubin, in J. Wasserman Michelangelo's Florence Pieta`, Princeton University Press, 2003, pp.217-222.

Scanning and Processing 3D Objects for Web Display. Farouk, M., I. El-Rifai, S. El-Tayar, H. El-Shishiny, M. Hosny, M. El-Rayes, J. Gomes, F. Giordano, H. Rushmeier, F. Bernardini, and K. Magerlein, 4th International Conference on 3D Digital Imaging and Modeling (3DIM '03) Banff, Alberta, October 2003.

Building a Digital  Model of Michelangelo's Florentine Pieta'. F. Bernardini, I. Martin, J. Mittleman, H. Rushmeier, G. Taubin. IEEE Computer Graphics & Applications, Jan. 2002.