Physically-based Simulation

High-Fidelity Sound Simulation for VR Gaming

Realistic sound effects are extremely critical in virtual reality to improve the sense of presence and realism of virtual environments. We present an interactive wave-based sound propagation system for generating accurate and realistic sound for virtual reality gaming applications. Our technique can handle large, open environments spanning hundreds of meters typically found in these applications. This system has been integrated with the Half-Life 2 game engine along with the Oculus-Rift HMD and the Xbox game controller, to enable users to experience high-quality sound effects, such as amplification, diffraction low-passing, high-order scattering, localization, and externalization, based on their interactions in the virtual environments.

Sound propagation in large indoor scenes

We have developed a novel hybrid approach that couples geometric and numerical acoustic techniques for interactive sound propagation in complex indoor and outdooor environments. This formulation is based on a combination of spatial and frequency decomposition of the sound field. The system is able to simulate high-fidelity acoustic effects such as diffraction, scattering, low-pass filtering behind obstruction, reverberation, and high-order reflections in large, complex indoor and outdoor environments.

Sound propagation in large outdoor scenes

We present a novel approach for wave-based sound propagation suitable for large, open spaces spanning hundreds of meters, with a small memory footprint. We demonstrate realistic acoustic effects such as diffraction, low-passed sound behind obstructions, focusing, scattering, high-order reflections, and echoes, on a variety of scenes.

Sound propagation for dynamic sources

We present a method for real-time sound propagation that captures all wave effects, including diffraction and reverberation, for multiple moving sources and a moving listener in a complex, static 3D scene.

Virtual and Augmented Reality

Efficient HRTF simulation

Inspired by newly introduced VR and AR systems such as Oculus Rift and Google glasses, we have developed an efficient technique to simulate personalized head related transfer functions (HRTFs) to generate high-quality spatial sound for interactive VR and AR applications. HRTFs model the scattering of sound from human ear and head, vary from person to person and responsible for giving a sense of direction for the incoming sound.


Spatial sound and Directional sources

Humans receive sound from the environment in a directional manner i.e. spatial sound. Similarly, most sound sources we come across in real-life are directional i.e. the radiate sound in certain directions. I have proposed an efficient approach for modeling spatial sound and dynamic, data-driven source directivity for interactive sound propagation in virtual environments.

GPGPU & Parallel Computing

Massively scalable wave solver on CPU-cluster

We present a massively parallel time-domain simulator to solve the acoustic wave equation in three dimensions on a distributed memory architecture. We highlight its performance on a cluster with up to a thousand cores and terabytes of memory. To the best of our knowledge, this is the fastest time-domain solver for simulating sound propagation for large, complex 3D scenes up to the highest audible frequency.


Efficient acoustic wave solver on GPUs

This work leverages the computational capabilities of the modern day GPU for solving the acoustic wave equation. It is the fastest single desktop-based solver for the wave equation for large, complex-shaped 3D scenes that generates results for auralization as well as visualization purposes.


Shape Modeling

Abstraction of man-made shapes

Man-made objects are ubiquitous in the real world and in virtual environments. While such objects can be very detailed, capturing every small feature, they are often identified and characterized by a small set of defining curves. We introduce a novel algorithm for abstracting three-dimensional geometric models using characteristic curves or contours as building blocks for the abstraction.

Visibility of noisy point cloud

We present a robust algorithm for estimating visibility from a given viewpoint for a point set containing concavities, non-uniformly spaced samples, and possibly corrupted with noise.


Human-Computer Interaction

Virtual music instruments

We present an interactive virtual percussion instrument system, that can be used by a group of collaborative users simultaneously to emulate playing music in real world while providing them with flexibility of virtual simulations.


Acoustic propagation in urban environments

Acoustic propagation in outdoor urban environments is a physically complex phenomenon due to the predominance of reflection, diffraction, and scattering. We present a full three-dimensional analysis of acoustic propagation in urban environment using the state-of-the-art numerical simulation method.



Mesostructure rendering

We present an efficient GPU technique for rendering rich geometric detail (e.g., surface mesostructure) of complex surfaces.