Radiosity fast#

This class represents an optimized radiosity implementation. It includes the following features:

It is optimized for speed
It supports various forms and relationships of patches
It supports BRDFs

Warning

This class contains a known issue in the energy exchange calculation for non-perfectly Lambertian surfaces. The problem will be fixed in a future release.

class sparrowpy.DirectionalRadiosityFast(walls_points, walls_normal, walls_up_vector, patches_points, patches_normal, patch_size, n_patches, patch_to_wall_ids)[source]#

Radiosity object for directional scattering coefficients.

Methods:

`bake_geometry`([ff_method, algorithm])	Bake the geometry by calculating all the form factors.
`calculate_energy_exchange`(speed_of_sound, ...)	Calculate the energy exchange between patches.
`collect_receiver_energy`(receiver_pos, ...[, ...])	Collect patch histograms as detected by receiver.
`from_polygon`(polygon_list, patch_size)	Create a Radiosity object for directional scattering coefficients.
`init_source_energy`(source_position[, ...])	Initializes the energy of the source at the patches.
`set_air_attenuation`(air_attenuation)	Set air attenuation factor in Np/m.
`set_wall_absorption`(wall_indexes, absorption)	Set the wall absorption.
`set_wall_scattering`(wall_indexes, ...)	Set the wall scattering (brdf).

Attributes:

`form_factors`	Return the form factor.
`n_bins`	Return the number of frequency bins.
`n_patches`	Return the total number of patches.
`n_walls`	Return the number of walls.
`patch_size`	Return the size of the patches.
`patches_area`	Return the area of the patches.
`patches_center`	Return the center of the patches.
`patches_normal`	Return the normal of the patches.
`patches_points`	Return the points of the patches.
`patches_size`	Return the size of the patches.
`speed_of_sound`	Return the speed of sound in m/s.
`visibility_matrix`	Return the visibility matrix.
`walls_area`	Return the area of the walls.
`walls_center`	Return the center of the walls.
`walls_normal`	Return the normal of the walls.
`walls_points`	Return the points of the walls.
`walls_up_vector`	Return the up vector of the walls.

bake_geometry(ff_method='universal', algorithm='order')[source]#

Bake the geometry by calculating all the form factors.

Parameters:

ff_method (str, optional) – defines the form factor calculation method, by default ‘universal’. No other methods are implemented yet.
algorithm (str, optional) – defines the algorithm used for Radiosity, by default ‘order’. No other algorithms are implemented yet.

calculate_energy_exchange(speed_of_sound, histogram_time_resolution, histogram_length, algorithm='order', max_depth=-1, recalculate=False)[source]#

Calculate the energy exchange between patches.

Parameters:

speed_of_sound (float) – speed of sound in m/s.
histogram_time_resolution (float) – time resolution of the histogram, e.g. 1/1000.
histogram_length (float) – duration of the histogram in seconds.
algorithm (str, optional) – defines the algorithm used for Radiosity, by default ‘order’. No other algorithms are implemented yet.
max_depth (int, optional) – maximum reflection order the be calculated. e.g. 0 means the first order reflection, by default -1
recalculate (bool, optional) – whether or not to recalculate energy propagation from source position, by default False.

collect_receiver_energy(receiver_pos, speed_of_sound, histogram_time_resolution, method='universal', propagation_fx=False)[source]#

Collect patch histograms as detected by receiver.

The receiver is assumed visible to all patches.

Parameters:

receiver_pos (np.ndarray) – receiver positions in cartesian coordinates of shape (n_receivers, 3).
speed_of_sound (float) – speed of sound in m/s.
histogram_time_resolution (float) – time resolution of the histogram, e.g. 1/1000.
method (str, optional) – defines the algorithm used for Radiosity, by default ‘order’. No other algorithms are implemented yet.
propagation_fx (bool, optional) – if true the sound propagation from patch to receiver is applied in the final histogram, by default False.

Returns:

histogram_out – the final energy histogram of shape (n_receivers, n_patches, n_bins, n_samples)

Return type:

np.ndarray

property form_factors#: Return the form factor.

classmethod from_polygon(polygon_list, patch_size)[source]#

Create a Radiosity object for directional scattering coefficients.

Parameters:

polygon_list (list[PatchesDirectional]) – list of patches
patch_size (float) – maximal patch size in meters.

init_source_energy(source_position: ndarray, ff_method='universal', algorithm='order')[source]#

Initializes the energy of the source at the patches.

Note that the geometry must be baked before calling this function. The source is assumed visible to all patches.

Parameters:

source_position (np.ndarray) – _description_
ff_method (str, optional) – defines the form factor calculation method, by default ‘universal’. No other methods are implemented yet.
algorithm (str, optional) – defines the algorithm used for Radiosity, by default ‘order’. No other algorithms are implemented yet.

property n_bins#: Return the number of frequency bins.

property n_patches#: Return the total number of patches.

property n_walls#: Return the number of walls.

property patch_size#: Return the size of the patches.

property patches_area#: Return the area of the patches.

property patches_center#: Return the center of the patches.

property patches_normal#: Return the normal of the patches.

property patches_points#: Return the points of the patches.

property patches_size#: Return the size of the patches.

set_air_attenuation(air_attenuation: FrequencyData)[source]#

Set air attenuation factor in Np/m.

If not called, no air attenuation is applied.

Parameters:: air_attenuation (pyfar.FrequencyData) – Air attenuation factor in Np/m.

set_wall_absorption(wall_indexes, absorption: FrequencyData)[source]#

Set the wall absorption.

If this is not called before baking, a default value of 0.0 is used.

Parameters:

wall_indexes (list[int]) – list of walls for the scattering data
absorption (pyfar.FrequencyData) – absorption coefficient of cshape (1, )

set_wall_scattering(wall_indexes: list[int], scattering: FrequencyData, sources: Coordinates, receivers: Coordinates)[source]#

Set the wall scattering (brdf).

See brdf for more information. Make sure the absorption is either included in the brdf or set independently via wall using set_wall_absorption.

Parameters:

wall_indexes (list[int]) – list of walls for the scattering data
scattering (pyfar.FrequencyData) – scattering data of cshape (n_sources, n_receivers)
sources (pyfar.Coordinates) – source coordinates
receivers (pyfar.Coordinates) – receiver coordinates

property speed_of_sound#: Return the speed of sound in m/s.

property visibility_matrix#: Return the visibility matrix.

property walls_area#: Return the area of the walls.

property walls_center#: Return the center of the walls.

property walls_normal#: Return the normal of the walls.

property walls_points#: Return the points of the walls.

property walls_up_vector#: Return the up vector of the walls.