Office: 6-225E Keller Hall

Phone: (612) 625-2013

Email: narain@umn.edu

I'm an assistant professor in the Department of Computer Science and Engineering at the University of Minnesota, Twin Cities. My research interests lie in numerical methods for computer graphics and animation, particularly focusing on efficient numerical optimization techniques for large-scale problems in physics-based animation and computational displays.

Previously, I received a B.Tech. from the Indian Institute of Technology Delhi and an M.S. and a Ph.D. from the University of North Carolina at Chapel Hill advised by Ming Lin. I was a postdoc at the University of California, Berkeley working with James O'Brien.

Spring 2016: *CSCI 4611: Programming Interactive Computer Graphics and Games*

Fall 2015: *CSCI 5980/8980: Physics-Based Animation*

Fall 2013 (at Berkeley): I gave two guest lectures on fluid simulation in *CS 184: Foundations of Computer Graphics*. Here are the slides: (1) Introduction and particle-based fluids, (2) grid-based fluids. They're okay.

Summer 2011 (at UNC): *COMP 116: Introduction to Scientific Computing*

- Rahul Narain, Rachel A. Albert, Abdullah Bulbul, Gregory J. Ward, Martin S. Banks, and James F. O'Brien.

"Optimal Presentation of Imagery with Focus Cues on Multi-Plane Displays".

*ACM Transactions on Graphics (Proc. SIGGRAPH)*, 2015. - Abhinav Golas, Rahul Narain, and Ming C. Lin.

"Continuum Modeling of Crowd Turbulence".

*Physical Review E*, 2014. - Woojong Koh, Rahul Narain, and James F. O'Brien.

"View-Dependent Adaptive Cloth Simulation".

*Proc. ACM SIGGRAPH / Eurographics Symposium on Computer Animation*, 2014.

… Here's my full list of publications.

**Multi-plane displays:** The conflict between stereo and focus cues in conventional 3D displays causes viewer discomfort and fatigue. Multi-plane displays, which show high-resolution images at several different focus distances, have the potential to overcome this problem. I'm interested in computational techniques to best reproduce arbitrary 3D scenes on such displays.

- R. Narain, R.A. Albert, M.A. Bulbul, G.J. Ward, M.S. Banks, and J.F. O'Brien. "Optimal Presentation of Imagery with Focus Cues on Multi-Plane Displays". SIGGRAPH 2015.
- M. Zannoli, G.D. Love, R. Narain, and M.S. Banks. "Blur and the Perception of Depth at Occlusions."
*Journal of Vision*, 2016.

**Adaptive remeshing:** Lots of physical phenomena show fine localized detail, from folds and wrinkles in cloth to crack patterns in shattering objects. Naturally, we'd like to refine the mesh resolution where there is detail and use coarser elements in smooth regions. The tricky part is anticipating where detail is *going* to emerge and refining sufficiently in advance, so you don't lose all the interesting dynamics.

- R. Narain, A. Samii, and J.F. O'Brien. "Adaptive Anisotropic Remeshing for Cloth Simulation". SIGGRAPH Asia 2012.
- R. Narain, T. Pfaff, and J.F. O'Brien. "Folding and Crumpling Adaptive Sheets". SIGGRAPH 2013.
- T. Pfaff, R. Narain, J.M. de Joya, and J.F. O'Brien. "Adaptive Tearing and Cracking of Thin Sheets". SIGGRAPH 2014.

**Fluids etc.:** Computer graphics has a rich history of techniques for simulating smoke, water, and other Newtonian fluids. I like to think about ways to simulate nontraditional fluid-like substances — like sand — and to simulate fluids in nontraditional ways — like vorticity-based and boundary element methods.

- R. Narain, J. Sewall, M. Carlson, and M.C. Lin. "Fast Animation of Turbulence Using Energy Transport and Procedural Synthesis". SIGGRAPH Asia 2008.
- R. Narain, A. Golas, and M.C. Lin. "Free-Flowing Granular Materials with Two-Way Solid Coupling". SIGGRAPH Asia 2010.
- A. Golas, R. Narain, J. Sewall, P. Krajcevski, P. Dubey, and M.C. Lin. "Large-Scale Fluid Simulation using Velocity-Vorticity Domain Decomposition". SIGGRAPH Asia 2012.

**Crowd simulation:** Crowds of pedestrians can in certain situations be well approximated as a continuous fluid-like system, particularly when the crowd is large and dense. In these cases we can apply the tools of continuum mechanics to model the behaviour of the crowd, enabling efficient simulations and revealing new insights.

- R. Narain, A. Golas, S. Curtis, and M.C. Lin. "Aggregate Dynamics for Dense Crowd Simulation". SIGGRAPH Asia 2009.
- A. Golas, R. Narain, and M.C. Lin. "Hybrid Long-Range Collision Avoidance for Crowd Simulation". I3D 2013 and
*TVCG*, 2014. - A. Golas, R. Narain, and M.C. Lin. "Continuum Modeling of Crowd Turbulence".
*Physical Review E*, 2014.