eradiate.scenes.atmosphere.HomogeneousAtmosphere#

class eradiate.scenes.atmosphere.HomogeneousAtmosphere(id='atmosphere', geometry='plane_parallel', sigma_s=_Nothing.NOTHING, sigma_a=0.0, phase=_Nothing.NOTHING)[source]#

Bases: Atmosphere

Homogeneous atmosphere scene element [homogeneous].

This class builds an atmosphere consisting of a homogeneous medium with customizable collision coefficients and phase function.

Parameters:

id (str, optional, default: "atmosphere") – Identifier of the current scene element.
geometry (SceneGeometry or dict or str, optional, default: "plane_parallel") – Parameters defining the basic geometry of the scene.
sigma_s (Spectrum or float, default: AirScatteringCoefficientSpectrum()) – Atmosphere scattering coefficient value.

Can be initialised with a dictionary processed by spectrum_factory.
sigma_a (Spectrum, default: 0.0 km**-1) – Atmosphere absorption coefficient value. Defaults disable absorption.

Can be initialised with a dictionary processed by spectrum_factory.
phase (PhaseFunction, default: RayleighPhaseFunction()) – Scattering phase function.

Can be initialised with a dictionary processed by phase_function_factory.

Fields:

id (str or None) – Identifier of the current scene element.
geometry (SceneGeometry) – Parameters defining the basic geometry of the scene.
sigma_s (Spectrum or float) – Atmosphere scattering coefficient value.
sigma_a (Spectrum) – Atmosphere absorption coefficient value.

eval_albedo(spectral_ctx)[source]#

Return albedo.

Parameters:: spectral_ctx (SpectralContext) – A spectral context data structure containing relevant spectral parameters (e.g. wavelength in monochromatic mode).
Returns:: quantity – Albedo.

eval_mfp(ctx)[source]#

Compute a typical scattering mean free path. This rough estimate can be used e.g. to compute a distance guaranteeing that the medium can be considered optically thick.

Parameters:: ctx (KernelDictContext) – A context data structure containing parameters relevant for kernel dictionary generation.
Returns:: mfp (quantity) – Mean free path estimate.

eval_sigma_a(sctx)[source]#

Return absorption coefficient.

Parameters:: sctx (SpectralContext) – A spectral context data structure containing relevant spectral parameters (e.g. wavelength in monochromatic mode).
Returns:: quantity – Absorption coefficient.

eval_sigma_s(sctx)[source]#

Return scattering coefficient.

Parameters:: sctx (SpectralContext) – A spectral context data structure containing relevant spectral parameters (e.g. wavelength in monochromatic mode).
Returns:: quantity – Scattering coefficient.

eval_sigma_t(sctx)[source]#

Return extinction coefficient.

Parameters:: sctx (SpectralContext) – A spectral context data structure containing relevant spectral parameters (e.g. wavelength in monochromatic mode).
Returns:: quantity – Extinction coefficient.

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

property bottom_altitude#

Returns:: quantity – Atmosphere bottom altitude.

property height#

Returns:: quantity – Atmosphere height.

property medium_id#

Returns:: str – ID of the medium associated with the atmosphere in the Mitsuba scene tree.

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.