[feature] Add Tregenza/Reinhart sky discretization scheme
Summary
Add Tregenza sky hemisphere (sky vault) and Reinhart sky-dome discretization scheme for light direction with optional patches amount control.
Current behavior
Fibonacci half sphere is not a classical discretization scheme for the sky sphere. i.e. early sky model used Lamberts's uniform sky model. This is not any more the current practice that use other discretization schemes as Tregenza / Reinhart
Desired behavior
Use Tregenza / Reinhart as default sky discretization scheme and Fibonacci as option.
Add Tregenza as option with 145 patches as default (as in designbuilder). Follow Subramaniam et al., 2017 description:
- 1-145 - the original Tragenza sky discretised into 145 patches.
- 2-577 - sky is discretised into 577 patches. This is the default option corresponding to Reinhart’s extension of the Tregenza sky, where the original 145 patches are subdivided into 4 subpatches, except at the zenith. MF:2 Reinhart subdivision scheme.
- 3-1297 - sky is discretised into 1297 patches. MF:3 Reinhart subdivision scheme.
- 4-2305 - sky is discretised into 2305 patches. This corresponding to Reinhart’s extension of the Tregenza sky, where the original 145 patches are subdivided into 16 subpatches, except at the zenith. MF:4 Reinhart subdivision scheme.
- 5-3601 - sky is discretised into 3601 patches. MF:5 Reinhart subdivision scheme.
- 6-5185 - sky is discretised into 5185 patches. MF:6 Reinhart subdivision scheme. This is the most detailed option and is recommended for use with the No sky line Right to Light calculation which requires a fine sub-division of the sky for accurate results
Finer resolutions using same subdivision scheme must be included (i.e. MF:8, MF:16) as they are present in the literature.
Eventually in the future offer the BRE/CIE as option for the sky discretization (see issue #120).
Sources
- Brian Goss, Ian Cole, Thomas Betts, Ralph Gottschalg, Irradiance modelling for individual cells of shaded solar photovoltaic arrays,Solar Energy,Volume 110, 2014,https://doi.org/10.1016/j.solener.2014.09.037
- John Mardaljevic, Mark Rylatt, Irradiation mapping of complex urban environments: an image-based approach, Energy and Buildings, Volume 35, Issue 1, 2003, Pages 27-35, https://doi.org/10.1016/S0378-7788(02)00077-4
- Gastellu-Etchegorry Jean-Philippe, DART User's manual (5.10.8) CESBIO
- https://designbuilder.co.uk/helpv7.3/Content/DaylightingCalculationOptions.htm
- Subramaniam, Sarith & Mistrick, Richard. (2017). A more accurate approach for calculating illuminance with daylight coefficients.