Henrik Philippi: Simulating Light in Virtual Reality
When designing products or buildings, it is often useful to get a visualization of the finished object before manufacturing. For this purpose, special visualization software can simulate light interactions to render a realistic image without taking on the cost of prototyping and photographing. Virtual Reality (VR) in the form of Head-mounted displays can give the user an immersive experience in which they can intuitively walk through a scene and look at it from different angles, perceive depth and even interact with objects in the virtual world. Unlike physically based visualizations, rendering in Virtual reality commonly relies on simpler techniques which cannot give an appropriate representation of materials under realistic lighting conditions.
Adopting the light transport algorithms used for visualization software to VR poses a challenge as these techniques are not meant to be used under constantly changing viewing angles and positions. This results in low frame rates and noisy images, giving an unpleasant experience to the user especially for unidirectional path tracing which is the most common light transport algorithm. Therefore, it would be nice to find techniques that can simulate light in virtual reality without the drawbacks of contemporary algorithms.
This PhD project strives to adopt and develop lighting simulation to be robust in VR and deal with the noise. By exploiting the similarities between the two rendered images for each eye and accumulating rendering samples over time, we hope to mitigate the noise induced by the random sampling used to simulate physically correct lighting. This also includes advancing alternative Light Simulation Algorithms like Photon Mapping, Instant Radiosity and Light fields which are better suited for changing viewing positions and could make realistic visualization possible in VR.
The project is carried out as part of the PRIME Innovative Training Network with Luxion as industrial Partner and Henrik Wann Jensen as Supervisor.