Parameter Reference
Parameters used in LUX daylight analysis. Automatically extracted from Revit models or provided via API.
Coordinate values use the XYZ coordinate system with Z pointing up. See Coordinate System for details.
Room Geometry
| Parameter | Description | Format | Default Value |
|---|---|---|---|
| Room boundary | 2D outline of the room at floor level | Array of coordinate pairs [[x1,y1], [x2,y2], ...] | Required |
| Floor height above terrain | Vertical position of the floor level | Float (meters) | Required |
| Roof height above terrain | Vertical position of the roof level | Float (meters) | Required |
Window Properties
| Parameter | Description | Format | Default Value |
|---|---|---|---|
| Window position | Center point of the window on the facade in XYZ coordinates (Z-up) | Coordinate pair [x1, y1, z1, x2, y2, z2] | Required, measured by the app |
| Window sill height | Distance from floor to bottom of window | Float (meters) | Required, measured by the app |
| Window frame ratio | Ratio of opaque area to total window area | Float (0-1) | Required |
| Window orientation | Cardinal direction the window faces | Float (degrees, 0-360°) | 288° |
How to measure | Coordinate System
Context & Obstructions
Obstruction mesh vertices use XYZ coordinates (Z-up). Direction angles define horizontal rotation in the XY plane.
| Parameter | Description | Format | Default Value |
|---|---|---|---|
| Horizon angle | Angular distance from horizontal line at the window reference point to surrounding obstructions | Array of angles [a1, a2, ...] or single float (degrees, 0-90°) | Required |
| Zenith angle | Angular distance from vertical line at the window reference point to overhead obstructions | Array of angles [a1, a2, ...] or single float (degrees, 0-90°) | Required |
How to measure | Coordinate System | Direction Angles
Material Properties
| Parameter | Description | Format | Default Value |
|---|---|---|---|
| Wall reflectance | Light reflectance of interior walls | Float (0.30-0.90) | 0.70 |
| Floor reflectance | Light reflectance of floor surface | Float (0.05-0.60) | 0.30 |
| Ceiling reflectance | Light reflectance of ceiling surface | Float (0.50-0.90) | 0.80 |
| Facade reflectance | Light reflectance of exterior facade | Float (0.10-0.60) | 0.30 |
| Terrain reflectance | Light reflectance of ground surface | Float (0.05-0.40) | 0.20 |
| Window frame reflectance | Light reflectance of window frames | Float (0.10-0.80) | 0.50 |
| Context reflectance | Light reflectance of surrounding buildings | Float (0.10-0.60) | 0.30 |
| Balcony reflectance | Light reflectance of balcony underside | Float (0.30-0.90) | 0.70 |
Still unclear?
Check parameter explanation for more details about each parameter.