Илиян is how my name is written in Cyrillic, the alphabet used in my mother tongue, Bulgarian. I can say I am a happy man, as I love the two most essential ingredients of my life – my girlfriend and my job. I like technology and gadgets, I'm fascinated by science. I appreciate clever design, beautiful pictures, and good food. I like skiing, driving cars, and I'm always in search for interesting travel destinations around the globe.


I do computer graphics – producing photo-realistic images of virtual 3D environments. I investigate methods for efficient physically based simulation of light transport, with the ultimate goal of rendering synthetic pictures that are indistinguishable from real photographs. This involves solving various problems arising from the physical nature of light, the mathematical models used to describe light transport, and the practical implementation of the simulation on a computer. I am pursuing a PhD degree in this field. Check out my publications.


Computer graphics is a fascinating synergy of science, technology and art, which comes in many different flavors. Solving complex mathematical equations and writing intricate computer programs can be very rewarding when the final result is a beautiful picture or a movie that can be also appreciated by non-technicians. Realistic image synthesis has applications in animated and feature films, commercials, architectural visualization, industrial design, games, and other areas.


I obtained a bachelor degree in computer science from Sofia University, Bulgaria, and a master degree from Saarland University, Germany, with an IMPRS fellowship from the Max-Planck Institute. I stayed in Saarbrücken as a doctoral student, again supported by IMPRS, and later became a researcher at the Intel Visual Computing Instute. I recently did a research internship at Disney Research Zürich and a R&D internship at Weta Digital. I have also worked as a consultant at Chaos Group, the creators of the V-Ray renderer. I currently work for Solid Angle, the company behind the Arnold renderer.

31 Mar 2014
Our paper on unifying points, beams, and paths for efficient volumetric rendering has been conditionally accepted to SIGGRAPH 2014.
23 Jan 2014
At EUROGRAPHICS 2014 we will present a course on path integration methods for light transport simulation.
27 Nov 2013
Published the slides from the SIGGRAPH Asia 2013 joint path sampling presentation.
1 Nov 2013
Our joint path sampling SIGGRAPH Asia 2013 paper is finally available, along with a cool interactive image comparison!
  Web: iliyan.com
LinkedIn: profile

In the real world, light particles are emitted from light sources, travel through space, and interact with the objects in the environment, until they finally reach the camera sensors (or our eyes), which in turn record their energy and convert it to a picture. This process can be simulated on a computer to produce a realistic image of a virtual environment with physically correct lighting.


The physical laws that govern light transport and the mathematical models that formalize the image rendering problem are generally well understood. However, performing an accurate simulation on a computer is a very challenging task in practice – billions of particles need to be tracked, each individual particle can interact with arbitrarily many objects, and only a small fraction of all particles eventually make it to the camera.


The primary focus of my research work can be very shortly summarized as investigating methods for the efficient discovery of light transport paths that contribute significant amounts of energy to the camera. Such methods can greatly improve the efficiency of the simulation, and thus speed-up rendering, as they concentrate the computational effort where it pays off most.