eradiate.scenes.measure.DistantFluxMeasure#

class eradiate.scenes.measure.DistantFluxMeasure(id='measure', spectral_cfg=_Nothing.NOTHING, spp=1000, split_spp=None, azimuth_convention=None, direction=[0, 0, 1], target=None, film_resolution=(32, 32))[source]#

Bases: eradiate.scenes.measure._core.Measure

Distant radiosity measure scene element [distant_flux].

This measure records the [spectral] radiosity (in W/m²[/nm]) at an infinite distance in a hemisphere defined by its direction parameter.

When used with a backward tracing algorithm, rays traced by the sensor target a shape which can be controlled through the target parameter. This feature is useful if one wants to compute the average flux leaving a particular subset of the scene.

Parameters

  • id (str, optional, default: "measure") – User-defined object identifier.

  • spectral_cfg (MeasureSpectralConfig or dict, default: MeasureSpectralConfig.new()) – Spectral configuration of the measure. Must match the current operational mode. Can be passed as a dictionary, which will be interpreted by MeasureSpectralConfig.from_dict().

  • spp (int, default: 1000) – Number of samples per pixel.

  • split_spp (int, optional) – If set, this measure will be split into multiple sensors, each with a sample count lower or equal to split_spp. This parameter should be used in single-precision modes when the sample count is higher than 100,000 (very high sample count might result in floating point number precision issues otherwise).

  • azimuth_convention (AzimuthConvention or str, optional, default: None) – Azimuth convention. If None, the global default configuration is used (see EradiateConfig).

  • direction (array-like, default: [0, 0, 1]) – A 3-vector defining the normal to the reference surface for which the exitant flux density is computed.

  • target (Target or dict or array-like, optional) – Target specification. The target can be specified using an array-like with 3 elements (which will be converted to a TargetPoint) or a dictionary interpreted by Target.convert(). If set to None (not recommended), the default target point selection method is used: rays will not target a particular region of the scene.

  • film_resolution (array-like, default: (32, 32)) – Film resolution as a (width, height) 2-tuple.

Fields

  • id (str or None) – User-defined object identifier.

  • spectral_cfg (MeasureSpectralConfig) – Spectral configuration of the measure.

  • spp (int) – Number of samples per pixel.

  • split_spp (int) – If set, this measure will be split into multiple sensors, each with a sample count lower or equal to split_spp.

  • azimuth_convention (AzimuthConvention) – Azimuth convention.

  • direction (array-like) – A 3-vector defining the normal to the reference surface for which the exitant flux density is computed.

  • target (Target or None) – Target specification.

Notes

  • Setting the target parameter is required to get meaningful results. Experiment classes should take care of setting it appropriately.

  • The film resolution can be adjusted to manually stratify film sampling and reduce variance in results. The default 32x32 is generally a good choice, but scenes with sharp reflection lobes may benefit from higher values.

is_distant()#

Return True iff measure records radiometric quantities at infinite distance.

is_split()#

Return True iff sample count split shall be activated.

kernel_dict(ctx)[source]#

Return a dictionary suitable for kernel scene configuration.

Parameters

ctx (KernelDictContext) – A context data structure containing parameters relevant for kernel dictionary generation.

Returns

KernelDict – Kernel dictionary which can be loaded as a Mitsuba object.

property film_resolution#

Getter for film resolution as a (int, int) pair.

Type

tuple

property sensor_dims#

List of sensor dimension labels.

Type

tuple of str

property var#

Post-processing variable field name and metadata.

Type

str, dict

property viewing_angles#

Viewing angles computed from stored film coordinates as a (width, height, 2) array. The last dimension is ordered as (zenith, azimuth).

Type

quantity