The Builder prepares the Rhino geometry for UrbanDaylight. The input envelopes represent the hull of the buildings. The Builder will create horizontal sections to create floor plates and then mesh the floors and input Breps to create sensor points for the simulation. Everything is packaged into a UrbanDaylight. Building format and then output under BLDGS. A picture of the component on the Grasshopper canvas is shown below.
In order to produce this “extra” geometry several user inputs are needed. They are specified by clicking on the black bar marked with the word “Settings”. A form for all required inputs will show up. The floor subdivision of the hull requires a floor to floor distance to be specified. “F2F” strict will force the Builder to create the cuts with the specified distance, otherwise best fit equal distance cuts will be computed and the real floor to floor distance may deviate slightly from the specified value. The facade opening ratios are specified below. Specifications can be made orientation dependent. North = North +- 25 degrees.
Under the Daylight tab target illuminance and blind systems are specified. These settings greatly influence the behavior of the building and its performance. Low target values are easier to full-fill and thus yield better performance under unchanged climatic conditions. A typical range for the Perimeter[lux] is between 300-500. A too high daylight exposure can lead to glare and comfort issue in the space and thus is similarly undesirable as a daylight under-supply. Thus, a max tolerable indoor illuminance can be specified to highlight over-supplied areas in the model.
UrbanDaylight can simulate dynamic blind systems. With the specified setpoint under “Pull blinds at” will dynamically pull a blind if the setpoint value is exceeded on the outside of the facade. The cutoff value specifies the fraction that is passing the blind system.
In the Meshing tab the spatial resolution of the simulations is specified. Envelope resolution specifies the average sensor point distance on the facade. A small value e.g 0.5 results in a very fine sampling rate on the facade. This increases simulation accuracy but also simulation time and space required on your hard disc. This parameter can not be 0 and a value around 1-2 is recommended.
The Rad file resolution is a very similar control. It controls the meshing resolution of the simulation scene geometry. If set to 0 the triangle count is reduced to a minimum. A low triangle count will increase simulation speed. This value should be set to 0 unless you have curved geometry. Then the value should be set to < or = the envelope mesh resolution.
The floor resolution controls the interior sampling rate [average sensor point distance]. A recommended value is around 1. Finer resolution will increase accuracy but will also slow down the simulations.