eradiate.scenes.measure.DistantFluxMeasure#

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

Bases: DistantMeasure

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") – Identifier of the current scene element.
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().
sampler ({"independent", "stratified", "multijitter", "orthogonal", "ldsampler"}, default: "independent") – Mitsuba sampler used to generate pseudo-random number sequences.
spp (int, default: 1000) – Number of samples per pixel.
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.
ray_offset (float or quantity, optional, default: None) – Manually control the distance between the target and ray origins. If unset, ray origins are positioned outside of the scene and this measure is rigorously distant.
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.
film_resolution (array-like, default: (32, 32)) – Film resolution as a (width, height) 2-tuple.

Fields:

id (str or None) – Identifier of the current scene element.
spectral_cfg (MeasureSpectralConfig) – Spectral configuration of the measure.
sampler (str) – Mitsuba sampler used to generate pseudo-random number sequences.
spp (int) – Number of samples per pixel.
target (Target or None) – Target specification.
ray_offset (quantity or None) – Manually control the distance between the target and ray origins.
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.

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.

traverse(callback)#

Traverse this scene element and collect kernel dictionary template and parameter update map contributions.

Parameters:: callback (SceneTraversal) – Callback data structure storing the collected data.

update()#: Enforce internal state consistency. This method should be called when fields are modified. It is automatically called as a post-init step.

property film_resolution#

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

Type:: tuple

property objects#

Map of child objects associated with this scene element.

Returns:: dict – A dictionary mapping object names to a corresponding object to be inserted in the Eradiate scene graph.

property params#

Returns:: dict[str, UpdateParameter] or None – A dictionary mapping parameter paths, consisting of dot-separated strings, to a corresponding update protocol.