Associate Team RTR2A :
Real-Time Rendering and Augmented Reality
Start: February 2004
The Teams:
- Bunraku, IRISA, Campus de Beaulieu,
35042 Rennes Cedex.
- Computer Graphics Group, University
of Central Florida, School of Computer Science
Computer Science Building, Room 251, Phone: (407) 823-2638
Scientific description of the collaboration
The first objective is real-time high fidelity rendering of dynamic
scenes. Rendering complex scenes using a classical graphics pipeline (Z-buffering,
Phong's shading model, multitexturing, etc.) can be efficiently performed with
commodity graphics cards. However, real-time rendering of scenes, for which
global illumination is computed, still is a challenge for many researchers.
Indeed, global illumination followed by a rendering step (that we call high
fidelity rendering) is a demanding process in terms of computing and memory
resources.
Computing global illumination amounts to solve the rendering equation
which is an integral equation. Unfortunately, this equation does not have an
analytic solution in general. Consequently, Monte Carlo integration is the method
of choice for solving it. However, Monte Carlo integration requires the computation
of many samples, which makes it demanding in terms of computation time. Our
objective is to propose an algorithm which allows for interactive high fidelity
rendering and global illumination.
Our approach makes use of ray tracing, Monte Carlo integration
and caching. It aims at extending the ``irradiance caching'' algorithm (Greg
Ward 1994). Note that this algorithm is based on the observation that the diffuse
component of radiance, reflected on a diffuse surface and due to indirect illumination,
changes very slowly on this surface. This allows to sparsely sample and to cache
the incoming radiances at these samples, then to reuse the cached samples to
estimate the incoming radiance at nearby points. This method is computationally
efficient since the sampling is sparse. However it is limited to diffuse indirect
lighting computation.
Our work consists in extending the irradiance caching approach to indirect
glossy global illumination. Our algorithm relies on ``radiance caching''. It
is based on the caching of directional incoming radiances. We have first designed
a new set of basis functions defined on the hemisphere to represent directional
incoming radiance and BRDFs (Gautron et al. 2004). This representation, along
with a new gradient-based interpolation method (Krivanek et al. 2004), are the
bases of our radiance caching-based algorithm. We are also experimenting with
spherical wavelets to represent BRDFs and incoming radiances. Our radiance caching
algorithm will intensively exploit the power of programmable GPUs (Gautron et
al. 2005), to make global illumination more interactive. .
The second objective is augmented reality. We aim at combining in real time
synthetic and real images. To this end, we propose to: calibrate the real images,
extract the light sources which lighted the real scenes, insert synthetic objects
in the real scene for which we dispose only of their images captured by a camera,
and finally light these synthetic objects with the extracted real light sources.
The result will help a user, supplied with a head mounted display, to see a
real scene augmented with synthetic objects lit homogeneously.
For now, our collaboration has tackled only real-time high fidelity
rendering. The results we obtained are:
- Proposal of new basis functions defined on the hemisphere: Hemispherical
Harmonics.
- High fidelity rendering using these functions and relying on the principle
of radiance cache: software version, GPU-based version, new methods for computing
irradiance and radiance gradients.
- Rendering and illumination of animated grass: method combining surface and
volume rendering techniques.
- Rendering Trees with Indirect Lighting in
Real Time.
- New method for computing sub-surface scattering, application to skin rendering.
People involved:
- SIAMES :
- Kadi Bouatouch, Professor, IFSIC, University of Rennes1
- Pascal Gautron, PhD student at IRISA. Supervisor : Kadi Bouatouch and
Sumanta Pattanaik
- Jaroslav Krivanek, PhD student at IRISA. Supervisor : Kadi Bouatouch
and Sumanta Pattanaik
- Julien Perret, PhD student at IRISA. Supervisor : Kadi Bouatouch and
Charles Hughes.
- Kévin Boulanger, Graduate student at IFSIC, University of Rennes
1. Supervisors : Kadi Bouatouch and Sumanta Pattanaik.
- Guillaume François, Graduate student at IFSIC, University of
Rennes 1. Supervisors : Kadi Bouatouch and Sumanta Pattanaik.
- Computer Graphics Group, UCF :
- Sumanta Pattanaik, Associate Professor, UCF
- Charles Hughes, Professor, UCF
- Erik Reinhard, Assistant Professor, UCF.
- James Burnett, PhD student . Supervisor : Charles Hughes
- MarK Colbert, PhD student . Supervisor : Sumanta Pattanaik.
- Jaakko Konttinen, PhD student . Supervisor : Sumanta Pattanaik.
- Yugang Min, PhD student . Supervisor : Sumanta Pattanaik.
- Brad Loos, PhD student.
Missions already carried out
- Orlando-->Rennes :
- The Professors Charles Hughes and Sumanta Pattanaik: stay of two weeks
in May and June 2004.
- The Professor SumantaPattanaik: stay of two weeks
in July 2008.
- Erik Reinhard: stay of 2 months in 2007 as a visiting professor (University of
Rennes 1).
- The professor Charles Hansen: stay of two weeks
in July 2008.
- The PhD students Mark Colbert and Jaakko Konttinen: stay of 2 months
between mid-May 2005 and mid-July 2005.
- The PhD student James Burnett: stay of 3 months, December 2005 to February
2005.
- Yugang Min: stay of 2 months, from 12th of May 2006 to 10th of August
2006.
- The PhD student Brad Loos: stay of 2.5 months, November 2008 to mid-January
2009.
- Rennes-->Orlando :
- Pascal Gautron: stay of 3 weeks in august 2004;
- Kadi Bouatouch: stay of one week: December 2004 and one week in 2005, one week in 2007.
- Jaroslav Krivanek: stay of 7 months, from july 2004 to August 2004.
- Julien Perret: stay of 5 months, from July 2004 to December 2004;
- Kévin Boulanger: stay of 6 months, from March 2005 to August
2005;
- Guillaume François: stay of 6 months, from March 2005 to August
2005.
- Guillaume François: stay of 2months, from April 1st 2006 to 31
May 2006
- Kévin Boulanger: stay of 2 months, from June 2006 to July 2006.
Publications
- Siggraph Skteches
-2006: P. Gautron, K. Bouatouch, S. Pattanaik, Temporal Radiance Caching,
SIGGRAPH 2006 Sketches
- 2006: Kévin Boulanger, Sumanta Pattanaik, Kadi Bouatouch, Rendering
Grass Terrains in Real-Time with Dynamic Lighting,
Siggraph sketch
- 2006: François Guillaume, Sumanta Pattanaik and Kadi Bouatouch,
Subsurface Texture Mapping, SIGGRAPH Sketches
- 2006: Jaroslav Krivanek, Jaakko Konttinen, Kadi Bouatouch, Sumanta Pattanaik,
Jiri Zara, Fast Approximation to Spherical Harmonics Rotation, SIGGRAPH
Sketches.
- 2005: P. Gautron, J. Krivànek, K. Bouatouch, S. Pattanaik, Radiance
Cache Splatting: A GPU-Friendly Global Illumination Algorithm
SIGGRAPH Sketch, August
- Journals
- 2009: Jonathan Brouillat,
Christian Bouville, Brad Loos, Charles Hansen, Kadi Bouatouch, A
Bayesian Monte Carlo Approach to Global Illumination, Accepted, to
appear in the Computer Graphics Forum Journal.
- 2009: Kévin Boulanger, Sumant pattanaik, Kadi Bouaotuch,
Rendering Grass in Real-Time with Dynamic Lighting, IEEE Computer
Graphics & Applications journal, Vol. 29, No. 1.
- 2008: Guillaume François, Sumanta Pattanaik ,
Kadi
Bouatouch , Gaspard Breton, Subsurface Texture Mapping, IEEE
Computer Graphics & Applications journal, Vol. 28, No. 1.
- 2007: Pascal Gautron, Kadi Bouatouch, Sumanta Pattanaik, Temporal
Radiance Caching, IEEE
Transaction on Visualization and Computer Graphics Journal., Vol. 12, No. 5, Septembre/Octobre, 2
- 2005: Krivánek Jaroslav, Gautron Pascal, Pattanaik
Sumanta, Bouatouch Kadi, Radiance Caching for Efficient Global
Illumination Computation, IEEE Transactions on Visualization and Computer
Graphics, Vol. 11, No. 5, September/October .
- Conferences
- 2009: M. Schott, V. Pegoraro, C. Hansen, K.
Boulanger, K. Bouatouch, A Directional Occlusion Shading Model
for Interactive Direct Volume Rendering, Eurographics/IEEE
Symposium on Viualization, June, Berlin.
- 2008: Kévin Boulanger, Kadi
Bouatouch, Sumant Pattanaik, Rendering Trees with Indirect Lighting in
Real Time,
In Proceedings of Eurographics Symposium on Rendering, June 2008.
- 2006: Jaroslav Krivánek, Kadi Bouatouch, Sumanta Pattanaik, and Jirí
Žára Making Radiance and Irradiance Caching Practical: Adaptive
Caching and Neighbor Clamping (Paper in Conference Proceedings) In Rendering
Techniques, Proceedings Eurographics
Symposium on Rendering, pp. 127-138. June 2006.
- 2006: Jaroslav Krivánek, Jaakko Konttinen, Sumanta Pattanaik, Kadi
Bouatouch, and Jirí Žára Fast Approximation to Spherical
Harmonic Rotation (Paper in Conference Proceedings) SCCG '06: Proceedings
of the 22nd spring conference on Computer graphics
- 2006: Kévin Boulanger, Kadi Bouatouch, Sumanta Pattanaik, ATIP: A
Tool for 3D Navigation inside a Single Image with Automatic Camera Calibration,
EG UK Theory and Practice of Computer Graphics
2006
- 2005: Krivánek Jaroslav, Gautron Pascal, Bouatouch Kadi, Pattanaik Sumanta, Improved Radiance Gradient Computation. In
Proceedings of Spring Conference on Computer Graphics SCCG,
p. 149-153..
- 2005: P. Gautron, J. Krivànek, K. Bouatouch, S.
Pattanaik, Radiance Cache Splatting: A GPU-Friendly Global Illumination
Algorithm, Proceedings of Eurographics Symposium
on Rendering, June.
- 2004: Gautron Pascal, Krivánek Jaroslav, Pattanaik
Sumanta, Bouatouch Kadi, A Novel Hemispherical Basis for Accurate and
Efficient Rendering, In Proceedings of Eurographics Symposium on
Rendering, EGSR2004, p. 321-330. June.
- 2004: Krivánek Jaroslav, Pattanaik Sumanta,
Žára Jiøí, Adaptive Mesh Subdivision for
Precomputed Radiance Transfer, In Proceedings of Spring Conference on Computer
Graphics SCCG 2004. Bratislava : Comenius University, p. 104-109.
- Research Reports
- 2006: P. Gautron, K. Bouatouch, S. Pattanaik, Temporal Radiance Caching,
Technical Report no. 1796, IRISA,
Rennes, France
- 2006: K. Boulanger, S. Pattanaik, K. Bouatouch, Rendering Grass in Real-Time
with Dynamic Light Sources and Shadows, Technical
Report no. 1809, July, IRISA, Rennes, France
- 2006: Guillaume François , Sumanta Pattanaik , Kadi Bouatouch ,
Gaspard Breton, Subsurface Texture Mapping, Technical
Report no. 1806, June 2006 / 28 pages.
- 2005: Jaroslav Krivánek, Jaakko Konttinen, Sumanta Pattanaik, Kadi Bouatouch,
Fast Approximation to Spherical Harmonic Rotation, Technical
Report no. 1728. IRISA, Rennes, France. June.
- 2004: Krivánek Jaroslav, Gautron Pascal, Pattanaik Sumanta, Bouatouch
Kadi, Radiance Caching for Efficient Global Illumination Computation , Technical
Report no. 1623. IRISA, Rennes, France. June.