eradiate.scenes.phase.HenyeyGreensteinPhaseFunction#

class eradiate.scenes.phase.HenyeyGreensteinPhaseFunction(id='phase', g=0.0)[source]#

Bases: PhaseFunction

Henyey-Greenstein phase function [hg].

The Henyey-Greenstein phase function [Henyey and Greenstein, 1941] models scattering in an isotropic medium. The scattering pattern is controlled by its \(g\) parameter, which is equal to the phase function’s asymmetry parameter (the mean cosine of the scattering angle): a positive (resp. negative) value corresponds to predominant forward (resp. backward) scattering.

Parameters:
  • id (str, optional, default: "phase") – Identifier of the current scene element.

  • g (Spectrum or dict or float, optional, default: 0.0) – Asymmetry parameter. Must be dimensionless. Must be in \(]-1, 1[\).

Fields:
  • id (str or None) – Identifier of the current scene element.

  • g (Spectrum) – Asymmetry parameter.

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 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.

property template#

Kernel dictionary template contents associated with this scene element.

Returns:

dict – A flat dictionary mapping dot-separated strings describing the path of an item in the nested scene dictionary to values. Values may be objects which can be directly used by the mitsuba.load_dict() function, or InitParameter instances which must be rendered.