Source code for eradiate.scenes.bsdfs._rpv

from __future__ import annotations

import attrs
import mitsuba as mi

from ._core import BSDF
from ..core import traverse
from ..spectra import Spectrum, spectrum_factory
from ... import validators
from ...attrs import documented, parse_docs
from ...kernel import TypeIdLookupStrategy, UpdateParameter

[docs]@parse_docs @attrs.define(eq=False, slots=False) class RPVBSDF(BSDF): """ RPV BSDF [``rpv``]. This BSDF implements the Rahman-Pinty-Verstraete (RPV) reflection model :cite:`Rahman1993CoupledSurfaceatmosphereReflectance,Pinty2000SurfaceAlbedoRetrieval`. It notably features a controllable back-scattering lobe (`hot spot`) characteristic of many natural land surfaces and is frequently used in Earth observation because of its simple parametrisation. See Also -------- :ref:`plugin-bsdf-rpv` Notes ----- * The default configuration is typical of grassland in the visible domain (:cite:`Rahman1993CoupledSurfaceatmosphereReflectance`, Table 1). * Parameter names are defined as per the symbols used in the Eradiate Scientific Handbook :cite:`EradiateScientificHandbook2020`. """ rho_0: Spectrum = documented( attrs.field( default=0.183, converter=spectrum_factory.converter("dimensionless"), validator=[ attrs.validators.instance_of(Spectrum), validators.has_quantity("dimensionless"), ], ), doc="Amplitude parameter. Must be dimensionless. " "Should be in :math:`[0, 1]`.", type=".Spectrum", init_type=".Spectrum or dict or float, optional", default="0.183", ) rho_c: Spectrum | None = documented( attrs.field( default=None, converter=attrs.converters.optional( spectrum_factory.converter("dimensionless") ), validator=attrs.validators.optional( [ attrs.validators.instance_of(Spectrum), validators.has_quantity("dimensionless"), ] ), ), doc="Hot spot parameter. Must be dimensionless. " r"Should be in :math:`[0, 1]`. If unset, :math:`\rho_\mathrm{c}` " r"defaults to the kernel plugin default (equal to :math:`\rho_0`).", type=".Spectrum or None", init_type=".Spectrum or dict or float or None, optional", default="None", ) k: Spectrum = documented( attrs.field( default=0.780, converter=spectrum_factory.converter("dimensionless"), validator=[ attrs.validators.instance_of(Spectrum), validators.has_quantity("dimensionless"), ], ), doc="Bowl-shape parameter. Must be dimensionless. " "Should be in :math:`[0, 2]`.", type=".Spectrum", init_type=".Spectrum or dict or float, optional", default="0.780", ) g: Spectrum = documented( attrs.field( default=-0.1, converter=spectrum_factory.converter("dimensionless"), validator=[ attrs.validators.instance_of(Spectrum), validators.has_quantity("dimensionless"), ], ), doc="Asymmetry parameter. Must be dimensionless. " "Should be in :math:`[-1, 1]`.", type=".Spectrum", init_type=".Spectrum or dict or float, optional", default="-0.1", ) @property def template(self) -> dict: # Inherit docstring objects = { "rho_0": traverse(self.rho_0)[0], "k": traverse(self.k)[0], "g": traverse(self.g)[0], } if self.rho_c is not None: objects["rho_c"] = traverse(self.rho_c)[0] result = {"type": "rpv"} for obj_key, obj_values in objects.items(): for key, value in obj_values.items(): result[f"{obj_key}.{key}"] = value if is not None: result["id"] = return result @property def params(self) -> dict[str, UpdateParameter]: # Inherit docstring objects = { "rho_0": traverse(self.rho_0)[1], "k": traverse(self.k)[1], "g": traverse(self.g)[1], } if self.rho_c is not None: objects["rho_c"] = traverse(self.rho_c)[1] result = {} for obj_key, obj_params in objects.items(): for key, param in obj_params.items(): result[f"{obj_key}.{key}"] = attrs.evolve( param, lookup_strategy=TypeIdLookupStrategy( node_type=mi.BSDF,, parameter_relpath=f"{obj_key}.{key}", ) if is not None else None, ) return result