Diagrid Generator
Diagrids are a structural facade system often used in high-rises for their ability to expand usable floor area, reduce the need for interior columns, and provide passive shading across the building envelope. While the Lunchbox plugin in Grasshopper does offer a basic Diagrid node, its functionality is quite limited to simple U and V inputs. I found this to be insufficient for real world applications where diagrids must respond to the locations of the floor plates (i.e. nodes of diagrids must align with beams in the floors), and may require varying spacing across varying heights of buildings.
I created the Diagrid Generator, which addresses these limitations by providing users with more flexibility of inputs, including number of floors, individual floor heights, and spacing between nodes. The output generates a diagrid which is structurally coherent and actually aligns with floor plates. The result is a diagrid model that can be integrated into architecture and structural models in Rhino and Revit.
Intended Users
Architects, structural engineers, and designers who are working on diagrid facade systems.
Inputs
- Building form (as a Rhino geometry).
- Floor level heights
- Number of nodes per floor
Outputs
- Diagrid geometry generated as individual curves which nodes (i.e. meeting points between curves) that align with the floor plates. The curves can be baked into Rhino and converted into piping or Revit geometry.
Process
The logic that creates a diagrid on a facade is fairly simple. First, you subdivide the floor plate into x number of segments, depending on how many nodes per floor are desired. Then, connect every other node to each other to create diagonals. The edge condition is where it gets more complex, as you must find the midpoint on each edge, and then draw diagonals from the nearest node. See the image below for a visualization.
I designed my script by just testing it on one face of the building form and then looping the same script through the other faces. This posed some difficulties, especially when trying to find relationships between the midpoint and the nearest node. There are a lot of nodes that handle things like ListeItem selection and edge cases. The inputs are highlighted in light green, while everything in purple runs in the background. One thing to take note of is that this script only works on building forms with 4 faces. An extension of this would be to create a script that can be applied to any number of faces.
Video Demo