voxcity.simulator_gpu.domain.Domain¶

class voxcity.simulator_gpu.domain.Domain(nx: int, ny: int, nz: int, dx: float = 1.0, dy: float = 1.0, dz: float = 1.0, origin: Tuple[float, float, float] = (0.0, 0.0, 0.0), origin_lat: float | None = None, origin_lon: float | None = None, rotation_angle: float = 0)¶

3D computational domain for solar radiation simulation.

The domain uses a regular grid aligned with VoxCity indices: - x (first index i/u): Row direction, increases toward North - y (second index j/v): Column direction, increases toward East - z (third index k): Vertical, increases Ground to Sky

nx, ny, nz: Number of grid cells in each direction

dx, dy, dz: Grid spacing in meters

origin¶: (x, y, z) coordinates of domain origin

nx¶

ny¶

nz¶

dx = 1.0¶

dy = 1.0¶

dz = 1.0¶

origin = (0.0, 0.0, 0.0)¶

origin_lat¶

origin_lon¶

rotation_angle = 0¶

x_min = 0.0¶

x_max¶

y_min = 0.0¶

y_max¶

z_min = 0.0¶

z_max¶

cell_volume = 1.0¶

topo_top¶

is_solid¶

is_tree¶

lad¶

plant_top¶

n_surfaces¶

set_flat_terrain(height: float = 0.0)¶: Set flat terrain at given height.

initialize_terrain(height: float = 0.0)¶: Alias for set_flat_terrain.

set_terrain_from_array(terrain_height: numpy.ndarray)¶

Set terrain from 2D numpy array of heights.

Parameters:: terrain_height – 2D array (nx, ny) of terrain heights in meters

Add a rectangular building to the domain.

Can be called with either range tuples or individual parameters:

Parameters:

x_range – (i_start, i_end) grid indices
y_range – (j_start, j_end) grid indices
z_range – (k_start, k_end) grid indices

Or with keyword arguments:: x_start, x_end: X grid indices y_start, y_end: Y grid indices height: Building height in meters (z_range computed from this)

set_lad_from_array(lad_array: numpy.ndarray)¶

Set Leaf Area Density from 3D numpy array.

Parameters:: lad_array – 3D array (nx, ny, nz) of LAD values (m^2/m^3)

set_from_voxel_data(voxel_data: numpy.ndarray, tree_code: int = -2, solid_codes: list | None = None)¶

Set domain from a 3D voxel data array.

Parameters:

voxel_data – 3D numpy array with voxel class codes
tree_code – Class code for trees (default -2)
solid_codes – List of codes that are solid (default: all non-zero except tree_code)

add_tree_box(x_range: Tuple[int, int], y_range: Tuple[int, int], z_range: Tuple[int, int], lad_value: float = 1.0)¶

Add a box-shaped tree canopy region to the domain.

This is a simpler alternative to add_tree() for rectangular tree regions.

Parameters:

x_range – Grid index ranges (start, end)
y_range – Grid index ranges (start, end)
z_range – Grid index ranges (start, end)
lad_value – Leaf Area Density value (m^2/m^3)

Add a simple tree with cylindrical trunk and spherical crown.

Parameters:

center – (x, y) position in meters
height – Total tree height in meters (optional, computed from crown+trunk)
crown_radius – Radius of crown in meters
crown_height – Height of crown sphere in meters
trunk_height – Height of trunk (no leaves) in meters
max_lad – Maximum LAD at crown center

Or with keyword arguments:: center_x, center_y: Position in meters lad: Alias for max_lad

get_cell_indices(point: voxcity.simulator_gpu.solar.core.Point3) → taichi.math.ivec3¶: Get grid cell indices for a point.

get_cell_center(i: taichi.i32, j: taichi.i32, k: taichi.i32) → voxcity.simulator_gpu.solar.core.Point3¶: Get center coordinates of grid cell.

is_inside(point: voxcity.simulator_gpu.solar.core.Point3) → taichi.i32¶: Check if point is inside domain.

is_cell_solid(i: taichi.i32, j: taichi.i32, k: taichi.i32) → taichi.i32¶: Check if cell is solid (building or terrain).

get_max_dist() → float¶: Get maximum ray distance (domain diagonal).

get_lad(i: taichi.i32, j: taichi.i32, k: taichi.i32) → taichi.f32¶: Get LAD value at cell.