Ladybug is a free and open source environmental plugin for Grasshopper to help designers create an environmentally-conscious architectural design. The initial step in the design process should be the weather data analysis; a thorough understanding of the weather data will, more likely, lead designers to high-performance design decisions.
Ladybug imports standard EnergyPlus Weather files (.EPW) in Grasshopper and provides a variety of 2D and 3D designer-friendly interactive graphics to support the decision-making process during the initial stages of design. The tool also provides further support for designers to test their initial design options for implications from radiation and sunlight-hours analyses results. Integration with Grasshopper allows for an almost instantaneous feedback on design modifications, and as it runs within the design environment, the information and analysis is interactive.
Here is Ladybug in a less than 5-minute video (http://www.youtube.com/watch?v=OEjwAyC2l_0)!
Ladybug started by Mostapha Sadeghipour Roudsari is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License. Based on a work at https://github.com/mostaphaRoudsari/ladybug.
It means you can copy, distribute and transmit the work or remix it to adapt the work. You can also use it to make commercial use of the work, BUT you must attribute that the work is based on Ladybug, and if you alter, transform, or build upon Ladybug, you may distribute the resulting work only under the same or similar license. This process will ensure that Ladybug and its future versions will stay free and accessible for everyone.
Group page: http://www.grasshopper3d.com/group/ladybug
Facebook page: https://www.facebook.com/LadyBugforGrasshopper
Ladybug on Twitter: @ladybug_tool