Custom Parameters allow you to override global script settings on a surface-by-surface basis. Instead of creating multiple versions of your Grasshopper script for different building conditions, you can control individual facade surfaces directly from Rhino using Attribute UserText.
How to Set Up Custom Parameters
- Generate the Template: Click the Create Custom Parameters button in the script’s Main Parameters block. This automatically attaches the required UserText keys to all GH-Facet-Facade -tagged surfaces in Rhino.
- Select the Surface: In your Rhino viewport, select the specific facade surface you want to customize.
- Open UserText: Navigate to the Rhino Properties Panel and click the Attribute UserText tab (the icon on the far right).
- Edit the Values: You will see a list of pre-populated keys. Double-click the Value column next to any key to enter your custom settings.
Supported Custom Parameters
| Parameter (Key) | What it Controls | Formatting / Pro-Tip |
| FloorStack | The individual floor heights for this specific surface. | Enter numbers separated by commas (e.g., 5.00, 3.70, 3.20). |
| Spacing | The panel widths or grid spacing of the facade. | Enter a single value for a uniform grid, or multiple numbers separated by commas for varied spacing. |
| FlipDirection | The layout direction of your panel spacing. | Changes which end of the surface the spacing pattern starts from, giving you exact layout control. |
| Header Height | The header height for the facade design. Measured from the top. | Applies a single value across the entire input surface. To vary this by floor, split the surface horizontally by floor. |
| Parapet/Sill Height | The parapet or sill height for the facade design. Measured from the bottom. | Applies a single value across the entire input surface. To vary this by floor, split the surface horizontally by floor. |
Note: If you leave a value blank in the UserText panel, Facet will automatically fall back and use the Global Parameter value defined inside the Grasshopper script.