This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Validation of the Cycles Engine for Creation of Physically Correct Lighting Models
Technical Paper
2019-01-1004
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
Vision is the primary sense used to navigate through this world when driving, walking, biking, or performing most tasks. and thus visibility is a critical concern in the design of roadways, pathways, vehicles, buildings, etc. and the investigation of accidents. In order to assess visibility, the accident scene can be documented under similar conditions. Geometric and photometric measurements can be taken for later analysis. Calibrated photographs or video of a recreated scene can be captured to illustrate the visibility at a later time. This process can often require significant coordination of the physical features at the scene. It can be difficult to precisely control the motion and timing of moving features such as pedestrians and vehicles. The result is fixed in that you capture specific scenarios with specific conditions with the selected field of view and perspective of the cameras used. Alternatively, three-dimensional computer modeling and physically-based rendering (PBR) can be used to recreate an accident scene geometry and lighting conditions. PBR is a rendering method to create synthetic images and video by accurately simulating how light interacts in the three-dimensional environment. Specifically, the process presented in this paper utilizes the Cycles render engine within Blender. This allows for the accident scene to be recreated in a three-dimensional environment including the natural and artificial light sources. As we are concerned with accurately representing the light in the scene, it is necessary to create light sources within Cycles that represent the real-world light sources. The light sources in Cycles are quantified by several variables, including strength, color, and size. The strength and size variables determine the self-emitted radiance of the light source and requires further explanation to determine the relationship between these variables in Cycles and real-world lighting quantities. The color variable describes the light color as either an RGB value or as a color temperature value. In this paper, we define and validate the relationship between strength units in Cycles and photometric quantities and illustrate that the lighting produced is based on the physics of light.
Recommended Content
| Technical Paper | A Method for Mapping a Light Source Utilizing HDR Imagery |
| Technical Paper | Night Visibility Video for Accident Reconstruction |
| Technical Paper | AFS Light Distribution Control |
Citation
Cornetto, A. and Suway, J., "Validation of the Cycles Engine for Creation of Physically Correct Lighting Models," SAE Technical Paper 2019-01-1004, 2019, https://doi.org/10.4271/2019-01-1004.Also In
References
- Suway , J. and Welcher , J. A Quantitative Method for Accurately Depicting Still Photographs or Video of a Night-Time Scene Utilizing Equivalent Contrast SAE Technical Paper 2016-01-1463 2016 10.4271/2016-01-1463 Guo , Q. and Liu , B. Simulation and Physical Measurement of Seamless Passenger Airbag Door Deployment SAE Technical Paper 2012-01-0082 2012 10.4271/2012-01-0082
- Holohan , R. , Billing , A. , and Murray , S. Nighttime Photography - Show It Like It Is SAE Technical Paper 890730 1989 10.4271/890730
- Krauss , D. , Kuzel , M. , Arndt , S. , and Delahunt , P. Validation of Digital Image Representations of Low-Illumination Scenes SAE Technical Paper 2006-01-1288 2006 10.4271/2006-01-1288
- Ayres , T.J. Psychophysical Validation of Photographic Representations SERA-Vol. 6, Safety Engineering and Risk Analysis Mintz F.J. 1996
- Todd , J. , Sala , J. , Heckman , G. , and Krauss , D. Validation of High Dynamic Range Photography as a Tool to Accurately Represent Low-Illumination Scenes SAE Technical Paper 2012-01-0078 2012 10.4271/2012-01-0078
- Hull , W. , Newton , B. , Macaw , C. , Pippen , D. et al. Night Visibility Video for Accident Reconstruction SAE Technical Paper 960895 1996 10.4271/960895
- Ulbricht , C. , Wilkie , A. , and Purgathofer , W. Verification of Physically Based Rendering Algorithms Computer Graphics Forum 26 237 255 2006
- Lafortune , E.P. and Willems , Y.D. A Theoretical Framework for Physically Based Rendering Computer Graphics Forum 13 2 97 107 1994
- Ward , G.J. The Radiance Lighting Simulation and Rendering System Proceedings of SIGGRAPH 94 Computer Graphics Proceedings, Annual Conference Series Orlando, FL ACM SIGGRAPH / ACM Press 1994 459 472
- Kang , S.B. 1997
- Neale , W. , Marr , J. , and Hessel , D. Nighttime Videographic Projection Mapping to Generate Photo-Realistic Simulation Environments SAE Technical Paper 2016-01-1415 2016 10.4271/2016-01-1415
- Tannous , C. Light Production Metrics of Radiation Sources European Journal of Physics 35 4 2014
- Illuminating Engineering Society of North America (IESNA) American National Standard Practice for Roadway Lighting New York IESNA 2000
- Green , M. and Odom , J.V. Forensic Vision with Application to Highway Safety Tucson, AZ Lawyers & Judges Pub 2008
- CIE 978-3-901906-47-3 2006