1. Low Latency Rendering with Dataflow Architectures EngD Project Sebastian Friston Supervisor: Anthony Steed

2. Motivation: latency in virtual environments Latency is the time between a user’s action and the response to this action Latency in VR reduces sensory coherence –This coherence is key for creating a sense of presence Latencies of 10-16 ms have been shown to have a significant negative effect –Latencies under 5 ms can be detected though

3. Motivation: latency in GPUs (Mine, 1993)

4. Motivation: latency in GPUs

5. The Rendering Continuum (Zwicker, et al. 2000)

6. Dataflow Processing

7. True-Parallel Execution No scheduler Space taken is proportional to all possible operations Resources are close by

8. Light Field Rendering (Gortler, et al. 1996)

9. Light Field Renderers Have been implemented on GPUs and FPGAs Captured with cameras or synthesized Most practical applications have been to use them as a cache for volume renders Current implementations are limited by memory (Birklbauer, et al 2013) (Regan, et al 1999)

10. Hardware Accelerated Light Field Renderer

11. Validation and Complications Validate our renderer with latency interaction experiment –Possibly investigate phenomena where scale is hard to judge in VR –Possibly continue studies into detection during head rotations Display will be difficult –Current displays have latencies of ~6 ms

12. Thank you (Birklbauer, et al. 2013)

14. References Mine, M. R. (1993). Characterization of end-to-end delays in head-mounted display systems. University of North Carolina at Chapel Hill Zwicker, M., Gross, M., & Pfister, H. (2000). A Survey and Classification of Real Time Rendering Methods. Birklbauer, C., Opelt, S., & Bimber, O. (2013). Rendering Gigaray Light Fields. Computer Graphics Forum, 32(2pt4), 469–478. doi:10.1111/cgf.12067 Gortler, S. J., Grzeszczuk, R., Szeliski, R., & Cohen, M. F. (1996). The lumigraph. In Proceedings of the 23rd annual conference on Computer graphics and interactive techniques - SIGGRAPH ’96 (pp. 43–54). New York, New York, USA: ACM Press. doi:10.1145/237170.237200 Regan, M. J. P., Miller, G. S. P., Rubin, S. M., & Kogelnik, C. (1999). A real-time low- latency hardware light-field renderer. In Proceedings of the 26th annual conference on Computer graphics and interactive techniques - SIGGRAPH ’99 (pp. 287–290). New York, USA: ACM Press. doi:10.1145/311535.311569