Making Tools: Angles of Incidence

I'm always looking for little hacks that help me solve design problems. This is especially important in the early stages of design, when the team wants to:

1. Quickly grasp all of the variables at hand for the task

and 2. Weigh ALL of the design options for the best solution. 


One of my favorite hacks has been using parametric modeling tools (such as Grasshopper) to do some of the tedious heavy-lifting. Grasshopper is great because once I've found a logic, I can apply it to any variable I want, and watch the results dynamically. Recently I was tasked with designing an optimized light shelf for a tower facade that would help best illuminate the deepest parts of offices in a high-rise tower. I wrote a simple script that would help me test any shape of light shelf at any time of day and see where light would reflect into the space. 

Here's the challenge. On our typical floor, the depth of the office goes deeper than proper daylighting levels can penetrate. 

I'm calling this a hack because most people think of Grasshopper as a 3D form-finding tool. In this case, I just use it as a calculator -- and to draw some lines in 2D. 

In a pinch, I'm a dirty scripter. Sorry... But anyway, here's the solution: 


But here are the important variables. I try to make the important stuff clean and off to the side so my friends and coworkers can use it too. 


The script allows me to set any shape profile of a light shelf to be analyzed. Setting the angle of the sun draws parallel rays from a set point until they strike the line of the shelf. Once the rays hit the shelf, the line calculates the angle of incidence and bounces off the space and into the office. When the rays strike the ceiling they reflected once more. 

Here it is testing a flat light shelf and a curved light shelf:



The results are by no means presentation-ready but they can help me quickly understand the behavior of any shape, what areas they are reflecting light into, and when. In the true spirit of concept design, I tested a million shapes before settling on a selection to show the team. After watching the bounces slide back and forth into the space, I decided a bit of reverse engineering was in order to come up with an optimized shape. 

If the aspiration of the light shelf was to aim light towards the ceiling in the deepest part of the space, maybe a curved profile could contain all of the angles needed to reflect light along this vector at different times throughout the day .


The script itself was not pretty, but at least it gave me a trail of breadcrumbs to guide me towards this 9% improvement in the daylighting of our tower. Check out how some of the early lobby design concepts here!