Large-Scale Solar Analysis: Useful methods for Rhino and Ladybug Tools

Large-Scale Solar Analysis

Solar studies at the city scale can be conducted easily with GIS and 2.5D data. But we love 3D. 

What about 3D CAD software like Rhinoceros and Ladybug Tools?

Many research papers categorize Ladybug Tools as a software appropriate at the building scale or neighborhood, but we explored how it works at the city scale.

The study conducted at GATE Institute, Sofia, considers the calculation of solar radiation in 3D at the city scale. The context includes the mountains around the city and 3D data for 150 000 buildings.

First of all, we relocate geometry closer to the origin and simplify geometry to edge minimum size equal or greater than 1 meter to reduce the range of numbers. To generate clean solids, building footprints in .shp format are extruded using Heron for Grasshopper.

The key parameter in the simulation is a face count of meshes dedicated for analysis, which is approximately 2,000,000 faces on a regular machine with 32 GB RAM. Increasing the RAM leads to the ability to analyze more faces. This principle can work for a single district where all building surfaces are evaluated with a 3-meter grid size or, for example, for a city where all the residential rooftops are analyzed. Therefore, two cases were considered at the city and district scales, respectively. 

As for the shading context, the Incident Radiation component allows adding a really large shading mesh. This can be very useful when there is a need to consider a hilly region that impacts shading patterns in the city. 

The final step visualizes enriched building data in a 3D Web environment using baked textures.

 

More detailed information...