Dr. G S Raghavendra, an Assistant Professor at IIIT Hyderabad’s Center for Visual Information Technology (CVIT) takes us on a virtual tour of the Didṛkṣā Lab and his work in scientific visualization and computational topology, that evolved from early onset scientific curiosity, spiced by passion for science fiction and classical literature.
Prof. Raghavendra joined IIIT Hyderabad in early 2025, fresh out of post-doctoral research at the Scientific Computing and Imaging Institute (SCI), University of Utah. At CVIT, his work is a continuation of significant research in scientific visualization, computational topology, topological data analysis, and its applications.
Visualize that weather app on your phone. Color-coded gradients of different parameters, crunched and modelled from massive grids of raw meteorological data, gives you complete clarity. Visualization uses algorithms to convert raw numbers into a visual map, served up in a manner that your brain instantly interprets.
Scientific visualization, he points out, has been there, starting with Leonardo da Vinci sketching internal parts of the human body. Today, domain scientists generate a lot of data, spatiotemporal in nature, that need to be proved either through experiments or by simulation. Data presented in visual form, helps domain scientists to reach conclusions; an iterative process that aids in re-running experiments, changing certain aspects and deriving fresh insights.
Chasing an Engineering Dream
His pursuit of engineering science and allied fields stems from early curiosity and a marked scientific temper. He recalls that his parents never pressured him to chase marks or certifications and gave him carte blanche in life choices. Since his father was in a transferable job, Prof. Raghavendra grew up in Bangalore with his grandparents, completing his schooling and Pre-University studies from the New Cambridge High School, Vijayanagar and National College.
Peer-pressure steered the self-driven youngster down the popular path of JEE and entrance exams. With a B.E in Information Technology from the National Institute of Technology Surathkal, he began his career as a software engineer with Infineon Technologies.
The youngster who grew up on science fiction quickly realized that his heart was in academia. This brought him to Indian Institute of Science Bangalore for his Masters and PhD in Computer science, under Prof. Vijay Natarajan. What struck him most about his tenure was the proficiency of the faculty and the ease of classroom interaction; that would later define his teaching style. He enjoyed his stints as a Research Fellow at IISc.’s Visualization and Graphics Lab and at IIIT Bangalore.
During his Masters, the researcher had an eventful collaboration with a PhD student from the Molecular Biophysics Unit. His thesis on Extraction of Robust Voids and Cavities in Proteins in structures would result in a book chapter in Visualization in Medicine and Life Sciences Part III. “The book cover chosen was our project image”, he adds.
Before commencing his PhD, he briefly returned to NIT Surathkal to teach three semesters as temporary faculty, that turned out to be, just the break he needed.
A significant PhD work
When he began his PhD thesis, the first problem that he worked on would lead to an application called Edit Distance between Merge Trees, which was published in the Transactions in Visualization and Computer Graphics journal. The work done before that got the Best Poster Award in Scientific Visualization Track at the IEEE Conference on Visualization (SciVis Track) 2017 and was later extended into a full paper. “After this, many research groups actually picked up the same problem or variations of it and came up with solutions. If I rate all the things which I have done, I would consider this my most significant work”, he observes.
In 2024, the researcher received a Commendation Certificate for Outstanding Thesis (2022-23) from IISc.’s Dept of CSA. “My philosophy is to publish something which is thorough and brings a fundamental solution. I may have published only six papers but the satisfaction is that the contribution has been substantial”. Among the conferences on Visualization deemed important that he attended, the topmost were the IEEE Conferences at Phoenix, Vancouver and Oklahoma. More recently, his visit to Euroviz at Nottingham was followed by three beautiful days of enjoying the iconic museums of Greenwich and London.
After a six-month tenure as post-doctoral researcher at IISc., he moved to the University of Utah as a Postdoctoral Researcher at the Scientific Computing and Imaging Institute (SCI), working with Prof. Bei Wang Phillips. As his postdoc tenure wound down to a close, he was already interviewing for faculty positions at Indian universities.
Visualizing under the Great Banyan
“IIIT-H closed my application process quickly and I enjoyed the interview. As a CS student, I knew about their strength in programming and the good work happening in CVIT. Prof. Jawahar and Prof. PJ Narayanan were eminent visitors at ICVGIP conferences and I had attended multiple sessions where IIIT-H students had presented their work”.
When Prof. Raghavendra moved to the IIIT-H campus, what immediately struck him was the warm and welcoming nature of his fraternity. “The consideration and support extended to me was very reassuring”, he notes. “I was also very impressed with the professionalism of our teaching assistants. I had taught a very large class in data structures last semester, with three faculty and twenty-one TAs. Our TAs have done a really good job in with course evaluations and handling so many last-minute details”.
Topology Bridges Math, Theory and System Building
Prof. Raghavendra pegs the Comparative Analysis of Topological Structures as his most interesting work. Topology, he explains removes some unnecessary details initially, to make processing easier. Think of that stick figure that you draw before you start filling in the layers of intricate details.
Computational topology starts with building skeletons of scientific data to compare or measure some scientific phenomenon across time; with time steps, to study and compare what has changed between these two times. With skeletonization, since the data size is small, processing is faster since the system requires lesser RAM and GPU. “In our lab, we chiefly design these comparative algorithms between structures. My PhD problem looked at one such algorithm where we built a comparative tool, probably the first of its kind. Once our work came out, there were twenty more methods which are similar to our work dealing with different aspects of the same problem”.
The area blends mathematics, theory, algorithms and system building. The two extremes of the spectrum, from pure theory to pure system building allows the student the bandwidth to build a software or tool, depending on their inclination. “It is interdisciplinary in the sense that domain scientists in biology, physics or climate sciences can design algorithms and get some actionable insights”, observes Prof. Raghavendra who is collaborating with a Pune-based company and has ongoing collaborations with his PhD advisor IISc. Prof Vijay Natarajan, and with Prashant Goswami, a faculty in BTH Sweden on graphics-related problems.
Didṛkṣā and the Reading Club
It was a reading group that met weekly to read papers that catalysed Prof. Raghavendra’s Didṛkṣā Lab. Somewhere between reading papers and technical conversations, was sown the seed of creating a lab with some resources where students could come together and ideate. The Sanskrit derivative, meaning the desire to see, dovetailed nicely with Visualisation’s first prerequisite, the desire to see the data.
“A thought-provoking question by Prof. Vasudeva Varma stayed with me”, he muses. “He asked me, what is that one problem which keeps you awake, that once solved, will make you feel that you have really arrived? For me, that is multi-field topology”, he reflects. How do you build models for situations with measurement of multiple quantities, with some inherent dependence between each of those quantities? For instance, when you measure temperature and pressure in a room, both are dependent on each other in some very non-trivial way. “This is a long-term topic that will keep re-running somewhere in my mind”. In the short term, for an ANRF Early Career Grant proposal, the researcher is working on algorithms to make them run on systems with lesser memory and improved time efficiency.
Work. Home. Hobbies. Repeat
Work, home and hobbies are three locus of attention that form the stabilizers in his life. “I make it a point to set aside time for my hobbies every day”, shares the bookwork, who enjoys a delightfully wide and eclectic range of reading choices, from classical literature in Sanskrit and Kannada to translations of Greek epics and Shakespeare’s popular tragedies that mixes nicely with biographies, science fiction novels and movies. He recalls spending many days, leafing through books in Bangalore’s City Central Library and the State Central Library in Cubbon Park.
Holidays and sightseeing are usually tacked on to conference visits. “I try to incorporate hiking spots or natural scenic destinations to my agenda, apart from visits to museums where I can spend an entire day. In India, I love travelling to destinations with significant art and architecture like the Ajanta and Ellora caves, the ancient temples at Badami temples, Thanjavur and Mahabalipuram”. Once a dedicated runner, his fitness regimen now includes the occasional short marathon run or walks on campus with his wife.
Prof. Raghavendra has this timely message for his students. He urges balancing traditional empirical learning techniques with using AI resources judiciously, emphasizing the importance of understanding the nuances of the problem and sharpening the intellect, over outsourcing brainwork to digital aids.
Deepa Shailendra is a freelance writer for interior design publications; an irreverent blogger, consultant editor and author of two coffee table books. A social entrepreneur who believes that we are the harbingers of the transformation and can bring the change to better our world.