Gaze Directed Hybrid Rendering using Photon Mapping
Authors
Just Kjeldgaard Pedersen, Simon ; Jensen, Jeppe
Term
4. term
Publication year
2009
Pages
189
Abstract
People see sharp detail mainly at the center of their vision, not in the periphery. This project tests whether computer graphics can leverage that by using an eye tracker to find the gaze point and render a small region around it in high quality, while reducing detail elsewhere without the viewer noticing. In preliminary tests, participants did not detect quality loss when a region of 20 degrees of visual angle around the gaze point was rendered in high quality. In the system, the gaze region uses global illumination with photon mapping (a method that simulates light bouncing), and the outer region uses local illumination with OpenGL (a simpler, faster technique). To gain further benefit, the project introduces a gaze-directed photon mapping algorithm that sends more photons toward the gaze region to increase photon density there. In real-time visual tests, 77% of participants preferred gaze-directed photon mapping over traditional photon mapping, and measurements showed up to an 85% increase in photons in the gaze region. Performance also improved: the hybrid approach with gaze-directed photon mapping achieved frame rates up to five times higher than rendering the whole screen with global illumination. Overall, gaze-directed hybrid rendering can deliver graphics that look just as good to viewers while lowering computation costs.
Vi ser skarpest i centrum af synsfeltet og mindre detaljeret i periferien. Projektet undersøger, om computergrafik kan udnytte dette ved at bruge øjensporing til at finde blikpunktet og gengive et lille område omkring det i høj kvalitet, mens kvaliteten sænkes i periferien uden at det bemærkes. I indledende tests bemærkede deltagerne ikke kvalitetstab, når et område på 20 grader synsvinkel omkring blikpunktet blev gengivet i høj kvalitet. I systemet gengives blikområdet med global illumination via photon mapping (en metode, der simulerer lysets refleksioner), mens det ydre område gengives med lokal illumination via OpenGL (en enklere og hurtigere teknik). For at udnytte dette fuldt ud blev der udviklet en blikstyret photon-mapping-algoritme, som styrer flere fotoner mod blikområdet og dermed øger fotontætheden. I realtidstests foretrak 77% af deltagerne blikstyret photon mapping frem for traditionel photon mapping, og målinger viste op til 85% flere fotoner i blikområdet. Ydelsen blev også bedre: den hybride tilgang med blikstyret photon mapping gav op til fem gange højere billedhastighed end at gengive hele skærmen med global illumination. Konklusionen er, at blikstyret hybridrendering kan levere grafik, der opleves lige så god, til lavere beregningsomkostninger.
[This apstract has been rewritten with the help of AI based on the project's original abstract]
Keywords
Perceptually ; Gaze ; Eye-tracking ; Photon ; Mapping ; Render ; Rendering ; Hybrid ; Ray-tracing ; Computer ; Graphics ; Adaptive ; Perception ; Point of regard ; Global Illumination ; Local Illumination ; OpenGL ; Perception ; Fokus ; Ray-tracing ; Grafik