Measuring Light Through Trees for Daylight Simulations

09 Jan 2017 Priji Balakrishnan ASD Daylight Modelling Simulation

PhD Student
Priji Balakrishnan, Architecture and Sustainable Design
J. Alstan Jakubiec, Assistant Professor, Architecture and Sustainable Design

Trees play a significant role in influencing both indoor and outdoor daylight availability. Current daylighting simulation practices in built environment design either model them as cones, spheres or cylinders with assumed reflectance values or omit them altogether.
Trees have complex optical properties and can moderate or scatter light, either reducing daylight availability or acting as a passive source of daylight. To accurately incorporate this effect into the built environment, the authors explore a low-cost method employing high dynamic range photography and automated image processing to measure two key variables of the tree crown that affect its optical properties: gap percentage and transmittance percentage.
These measured key variables can be used in daylight simulation platforms such as Radiance to geometrically model the crown of a tree and specify its optical properties, thus representing the daylight moderating effects and dappled patterns of trees in the built environment.

Read more here.