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 define, documented
from ...kernel import SceneParameter, SearchSceneParameter
[docs]
@define(eq=False, slots=False)
class MaignanBSDF(BSDF):
"""
Maignan polarized BSDF [``maignan``].
This plugin implements the reflection model proposed by
:cite:`Maignan2009PolarizedReflectance`. The model is based on fits to
POLDER observations and combines a BRDF with the Fresnel
reflectance matrix (see Eq. 21 in :cite:`Maignan2009PolarizedReflectance`).
"""
C: Spectrum = documented(
attrs.field(
default=5.0,
converter=spectrum_factory.converter("reflectance"),
validator=[
attrs.validators.instance_of(Spectrum),
validators.has_quantity("reflectance"),
],
),
doc="Scaling parameter (*C*) of the Maignan BPDF model. Must be "
"positive (typically in [4, 8].)",
type=".Spectrum",
init_type=".Spectrum or dict or float, optional",
default="5.0",
)
ndvi: Spectrum = documented(
attrs.field(
default=0.8,
converter=spectrum_factory.converter("reflectance"),
validator=[
attrs.validators.instance_of(Spectrum),
validators.has_quantity("reflectance"),
],
),
doc="NDVI parameter (*ν*) of the Maignan BPDF model. Must be "
"in :math:`[0, 1]`.)",
type=".Spectrum",
init_type=".Spectrum or dict or float, optional",
default="1.0",
)
refr_re: Spectrum = documented(
attrs.field(
default=1.5,
converter=spectrum_factory.converter("reflectance"),
validator=[
attrs.validators.instance_of(Spectrum),
validators.has_quantity("reflectance"),
],
),
doc="Real part of the surface's refractive index. Must be positive.)",
type=".Spectrum",
init_type=".Spectrum or dict or float, optional",
default="1.5",
)
refr_im: Spectrum = documented(
attrs.field(
default=0.0,
converter=spectrum_factory.converter("reflectance"),
validator=[
attrs.validators.instance_of(Spectrum),
validators.has_quantity("reflectance"),
],
),
doc="Imaginary part of the surface's refractive index. Must be positive.)",
type=".Spectrum",
init_type=".Spectrum or dict or float, optional",
default="0.0",
)
ext_ior: Spectrum = documented(
attrs.field(
default=1.000277,
converter=spectrum_factory.converter("reflectance"),
validator=[
attrs.validators.instance_of(Spectrum),
validators.has_quantity("reflectance"),
],
),
doc="Exterior index of refraction. The imaginary part is assumed to be 0.",
type=".Spectrum",
init_type=".Spectrum or dict or float, optional",
default="1.000277",
)
@property
def template(self) -> dict:
# Inherit docstring
result = {"type": "maignan"}
for obj_name in ["C", "ndvi", "refr_re", "refr_im", "ext_ior"]:
kdict = traverse(getattr(self, obj_name))[0]
for key, value in kdict.items():
result[f"{obj_name}.{key}"] = value
if self.id is not None:
result["id"] = self.id
return result
@property
def params(self) -> dict[str, SceneParameter]:
# Inherit docstring
result = {}
for obj_name in ["C", "ndvi", "refr_re", "refr_im", "ext_ior"]:
params = traverse(getattr(self, obj_name))[1].data
for key, param in params.items():
result[f"{obj_name}.{key}"] = attrs.evolve(
param,
search=SearchSceneParameter(
node_type=mi.BSDF,
node_id=self.id,
parameter_relpath=f"{obj_name}.{key}",
)
if self.id is not None
else None,
)
return result
Eradiate