I tend to have a lot of different research interests, but the common theme that ties everything together is a desire to understand and model human and animal behavior, either with computer graphics and animation or on mechanical devices like humanoid robots. Lately, my perspective has moved towards a systems-based approach rather than looking at isolated components. However, in order to do any research at a wider holistic level, I often had to work on individual components first to make sure they are modeled correctly. The following are research projects that I've worked on and continue to be interested in while working in graduate school at the University of Toronto and at my current employment at the Honda Research Institute USA. Most recent research activity is listed first. Due to company confidentiality, I can only list the projects that have been publicly presented - I can't tell you about all the fun secret stuff I work on ;).
Intelligent Systems for Humanoid Robots
At my current work at the Honda Research Institute USA, I work on mult-agent intelligent systems for modeling human-robot interactions and complex tasks on the 2000 Honda ASIMO humanoid robot. Our goal is to develop autonomous robots using well-designed and reusable interaction models and a variety of perceptual, decision-making and motor control components. I currently am the project leader for human-robot interaction and intelligent systems integration. We've written several major software systems for handling environment maps, sensor fusion, task organization, robot control, and inter-agent communication.
Ng-Thow-Hing, V., T. List, K. Thórisson, J. Lim, J. Wormer, Design and Evaluation of Communication Middleware in a Humanoid Robot Architecture, in IROS 2007 Workshop on Measures and Procedures for the Evaluation of Robot Architectures and Middleware, Oct. 29, 2007, San Diego, CA, 2007.
Yang, A., H. Gonzalez-Banos, V. Ng-Thow-Hing, J. Davis, RoboTalk: Controlling Arms, Bases and Androids through a Single Motion Interface, in Proceedings of the 12th International Conference on Advanced Robotics, July 18-20, Seattle, 2005.
Computational Palaeontology
This project was a collaboration with John Hutchinson (Royal Veterinary College, University of London) and Frank "Clay" Anderson (Stanford University). It originated during a cafe chat around 2003 at Starbucks in Mountain View, CA. I was developing some mass models for my work in Digital Human Modeling at Honda, and thought that by combining these mass models with the B-spline solid model I used for muscle, we could create a very versatile shape primitive for estimating mass properties of body tissue in animals for both extant and extinct species. Well, 4 years later in 2007 we finally published our work with the developed mass set model applied to a Tyrannosaurus rex skeleton and validated with an ostrich carcass. I really enjoyed this project and it was done in my off-hours (Honda's not really into dinosaurs), so it was truly a labour of love.
Ng-Thow-Hing, V., F. C. Anderson., and J. R. Hutchinson, Mass Sets for Interactive Computation of Inertial Parameters for Rigid and Deformable Body Segments, in IX International Symposium on Computer Simulation in Biomechanics, July 2-4, Sydney, Australia, 2003.
Motion Planning for Robots
Motion planning is a very important step prior to actual execution of motion on a robot. In order to design motion trajectories to send to a robot's joints, the trajectories to accomplish the task goal must avoid self-collisions, collisions with the environment and respect kinematic joint limits. I've worked on methods for planning tasks that involve switching between different modalities of motion (like walking and pushing). My main goal is to develop good modes of manipulation for a robot to accomplish higher level complex tasks. This work is done at the Honda Research Institute, USA with my former interns, Kris Hauser and Evan Drumwright.
Drumwright, E., V. Ng-Thow-Hing. Toward Interactive Reaching in Static Environments for Humanoid Robots, in IROS 2006, Beijing, China, 2006.
Complex Task Modeling for Humanoid Robots
The control algorithms for various motor tasks on a robot can vary widely depending on the goals of each task. They can range from simple joint angle trajectories to achieve certain poses, to pointing commands that require task-space control variables as well as perceptual information about objects in the environment. Evan Drumwright and I developed a Task Matrix that is a framework to unify these task programs with a simple, parameterized robot independent abstract interface. The Task Matrix can handle concurrency, conflict resolution, and can allow complex tasks to be assembled from simpler ones. Recently, the Task Matrix was made to work with the humanoid robot ASIMO. This project originated at the Honda Research Institute, and Evan has continued with the work into his PhD thesis. I am also actively developing the Task Matrix for my own research at Honda.
Wei Shao and I worked on a joint component model to more accurately model the complexity of human joints. With this model, we could build complex joints, such as in the human spine, shoulder and knee. These joints could be animated at real-time rates and can be used in interactive applications. I also worked on developing automatic methods for building subject-specific skeletons from motion captured data with Jianbo Peng.
Ng-Thow-Hing, V. Revisiting the Standard Joint Hierarchy: Improving Realistic Modeling of Articulated Characters, lecture at Game Developers Conference, San Jose, CA, March 22-26, 2004.
Ng-Thow-Hing, V., and W. Shao, Modular Components for Detailed Kinematic Modelling of Joints, International Society of Biomechanics XIXth Congress, July 6-11, 2003.
Ng-Thow-Hing, V., and J. Peng, Automated Subject-specific Scaling of Skeletons to Motion-Captured Markers, in IV World Congress of Biomechanics, poster presentation, Calgary Aug. 4-9, 2002.
Musculo-tendon Modeling for humans and animals
Although this topic was my first passion for research, it continues to still intrigue and excite me. My current work with humanoid robots makes it difficult to get back into this, but it hasn't stopped me from developing new ideas in whatever spare time I have left these days. I continue to collaborate with my co-authors from my grad school days as they have taken my original models and extended its application to other soft tissues. When I first started this topic, directly considering anatomy for modeling animals in computer graphics and animation was still unheard of. Most computer graphics were better at mechanical devices like cars and robots. Now we've almost got it right, but there is still something missing, and I hope continued work on building better underlying anatomical rigs for computer graphics creatures will be done.
Selected publications:
Teran, J., S. Blemker, V. Ng-Thow-Hing, R. Fedkiw, Finite volume methods for the simulation of skeletal muscle, in Proceedings of the 2003 ACM SIGGRAPH/Eurographics Symposium on Computer Animation, pages 68-74, 2003.
Agur, A., V. Ng-Thow-Hing, K. Ball, E. Fiume, and N. McKee, Documentation and Three-Dimensional Modelling of Human Soleus Muscle Architecture, Clinical Anatomy, Vol. 16, No. 4, pages 285-293, June 2003.
Ng-Thow-Hing, V. and E. Fiume, Application-specific Muscle Representations, in Proceedings of Graphics Interface 2002, (editor) W. Stűrzlinger and M. McCool, pages 107-115, 2002.
Ng-Thow-Hing, V., and E. Fiume, B-spline Solids as physical and geometric muscle models for musculoskeletal systems, in Proceedings of the VIIth International Symposium of Computer Simulation in Biomechanics, pages 68-71, 1999. Winner of Andrzej Komor New Investigator Award
MSc. Thesis: A Biomechanical Musculotendon Model for Animating Articulated Objects, University of Toronto, Department of Computer Science, supervisor: Eugene Fiume, January 1994.
Physics-Based Animation Systems
During my PhD thesis (1994-2000) at the University of Toronto, I co-developed with Petros Faloutsos a physics-based animation system called DANCE (Dynamic Animation and Control Environment). DANCE could be extended by plug-ins and featured abstract interfaces for controllers, numerical integrators and physical models. It could be used as a physics-simulation playground for testing out a variety of different ideas from virtual stuntmen to biomechanical models of muscle. This was a formative experience for me, as it was this project that I really started building plug-in based frameworks with abstract component interfaces in my software.
Since then, DANCE has subsequently been extended and improved by Ari Shapiro and has its own home page at UCLA.
Ng-Thow-Hing, V., and P. Faloutsos, Dynamic Animation and Control Environment (DANCE), Siggraph Technical Sketch, in Siggraph Conference Abstracts and Applications, page 198, 2000.
Ng-Thow-Hing, V., and P. Faloutsos, DANCE: dynamic animation and control environment, in Graphics Interface ’99 Poster Abstracts¸ poster presentation, pages 31-32, 1999.
