Our built-in antivirus scanned this download and rated it as virus free. This free tool was originally created by Timur Dogan. The most popular version of the UrbanDaylight for Rhino 1.1. UrbanDaylight for Rhino is included in Photo & Graphics Tools.
From the developer:
The UrbanDaylight is a Rhino5 and Grasshopper plugin that allows designers to simulate and evaluate the daylight potential of large urban designs. The tool automates exterior DAYSIM simulations for all buildings in the city model. Given the solar radiation on the facades, it uses a generalized impulse response to compute the interior illumination on an hour-by-hour basis. This allows us to use the data for climate-based metrics.
You may want to check out more software, such as Rhino RDK, SimLab 3D PDF From Rhino or X-55 Rhino, which might be related to UrbanDaylight for Rhino.