dragonfly_uwg.terrain module

class dragonfly_uwg.terrain.Terrain(geometry, pavement_albedo=0.1, pavement_thickness=0.5, pavement_conductivity=1.0, pavement_heat_capacity=1600000.0)[source]

Bases: object

Object representing the terrain on which an urban area sits.

Note

[1] Street, Michael A. (2013). Comparison of simplified models of urban climate for improved prediction of building energy use in cities. Thesis (S.M. in Building Technology) - Massachusetts Institute of Technology, Dept. of Architecture, http://hdl.handle.net/1721.1/82284

Parameters

  • geometry – An array of ladybug_geometry Face3D objects that together represent the terrain. This should include the entire area of the site, including that beneath building footprints.

  • pavement_albedo – A number between 0 and 1 that represents the albedo (reflectivity) of the pavement. (Default: 0.1, typical of fresh asphalt).

  • pavement_thickness – A number that represents the thickness of the pavement material in meters. (Default: 0.5 meters).

  • pavement_conductivity – A number representing the conductivity of the pavement material in W/m-K. (Default: 1 W/m-K, typical of asphalt).

  • pavement_heat_capacity – A number representing the volumetric heat capacity of the pavement material in J/m3-K. This is the number of joules needed to raise one cubic meter of the material by 1 degree Kelvin. (Default: 1.6e6 J/m3-K, typical of asphalt).

Properties:

  • geometry

  • pavement_albedo

  • pavement_thickness

  • pavement_conductivity

  • pavement_heat_capacity

  • polygon2ds

  • area

  • horizontal_area

  • characteristic_length

  • min

  • max

ToString()[source]

Overwrite .NET ToString method.

duplicate()[source]

Get a copy of this object.

classmethod from_building_bounding_rect(buildings)[source]

Initialize a Terrain from a list of dragonfly Buildings.

Parameters

buildings – An array of dragonfly Buildings around which a bounding rectangle will be computed to produce terrain geometry.

classmethod from_dict(data)[source]

Initialize a Terrain from a dictionary.

Parameters

data – A dictionary representation of a Terrain object in the format below.

{
"type": 'Terrain',
"geometry": [],  # array for Face3D for the terrain surface
"pavement_albedo": 0.15,  # number for the pavement albedo
"pavement_thickness": 0.75,  # pavement thickness in meters
"pavement_conductivity": 1.0,  # pavement conductivity in W/m2-K
"pavement_heat_capacity": 1600000  # volumetric heat capacity in J/m3-K
}
move(moving_vec)[source]

Move this Terrain along a vector.

Parameters

moving_vec – A ladybug_geometry Vector3D with the direction and distance to move the object.

reflect(plane)[source]

Reflect this Terrain across a plane.

Parameters

plane – A ladybug_geometry Plane across which the object will be reflected.

rotate_xy(angle, origin)[source]

Rotate this Terrain counterclockwise in the XY plane by a certain angle.

Parameters

  • angle – An angle in degrees.

  • origin – A ladybug_geometry Point3D for the origin around which the object will be rotated.

scale(factor, origin=None)[source]

Scale this Terrain by a factor from an origin point.

Parameters

  • factor – A number representing how much the object should be scaled.

  • origin – A ladybug_geometry Point3D representing the origin from which to scale. If None, it will be scaled from the World origin (0, 0, 0).

to_dict()[source]

Get Terrain as a dictionary.

property area

Get a number for the total surface area of the Terrain.

property characteristic_length

Get a number for the characteristic length.

This is the linear dimension of the side of a square that encompasses the neighborhood.

property geometry

Get a tuple of Face3D objects that together represent the Terrain.

property horizontal_area

Get a number for the horizontal area of the urban Terrain surface.

This is projected into the XY plane.

property max

Get a Point2D for the max bounding rectangle vertex in the XY plane.

property min

Get a Point2D for the min bounding rectangle vertex in the XY plane.

property pavement_albedo

Get or set a number between 0 and 1 for the pavement albedo (reflectivity).

property pavement_conductivity

Get or set a number for the pavement conductivity in W/m-K.

property pavement_heat_capacity

Get or set a number for the pavement volumetric heat capacity in J/m3-K.

property pavement_thickness

Get or set a number for the pavement thickness in meters.

property polygon2ds

Get a tuple of Polygon2D objects that together represent the Terrain.