Multi-pixel distant radiancemeter sensor (mpdistant)

Parameter	Type	Description	Flags
to_world	transform	Sensor-to-world transformation matrix.
direction	vector	Alternative (and exclusive) to to_world. Direction orienting the sensor’s reference hemisphere.
target	point or nested shape plugin	Optional. Define the ray target sampling strategy. If this parameter is unset, ray target points are sampled uniformly on the cross section of the scene’s bounding sphere. If a point is passed, rays will target it. If a shape plugin is passed, ray target points will be sampled from its surface.
target_radius	float	Optional. If a point target is used, setting this parameter to a positive value will turn the sensor into a distant radiometer with a fixed field of view defined as the cross section of a sphere of radius target_radius and centered at target. Otherwise, the single point target is targeted.
srf	spectrum	Sensor Response Function that defines the spectral sensitivity of the sensor (Default: none)

This sensor plugin implements a distant directional sensor which records radiation leaving the scene in a given direction. It records the spectral radiance leaving the scene in the specified direction. In its default version, it is the adjoint to the directional emitter.

By default, ray target points are sampled from the cross section of the scene’s bounding sphere. The target parameter can be set to restrict ray target sampling to a specific subregion of the scene.

Ray origins are positioned outside of the scene’s geometry.

If the film size is larger than 1×1, film coordinates are mapped to the (u,v) coordinates of the target shape.

Warning

If this sensor is used with a targeting strategy leading to rays not hitting the scene’s geometry (e.g. default targeting strategy), it will pick up ambient emitter radiance samples (or zero values if no ambient emitter is defined). Therefore, it is almost always preferable to use a non-default targeting strategy.