from __future__ import annotations
import warnings
import attrs
import mitsuba as mi
from ._core import Surface
from ..bsdfs import BSDF, LambertianBSDF, bsdf_factory
from ..core import Ref, SceneTraversal, traverse
from ..shapes import RectangleShape, SphereShape, shape_factory
from ...attrs import define, documented
from ...exceptions import OverriddenValueWarning, TraversalError
from ...kernel import TypeIdLookupStrategy, UpdateParameter
[docs]
@define(eq=False, slots=False)
class BasicSurface(Surface):
"""
Basic surface [``basic``].
A basic surface description consisting of a single shape and BSDF.
"""
shape: None | RectangleShape | SphereShape = documented(
attrs.field(
default=None,
converter=attrs.converters.optional(shape_factory.convert),
validator=attrs.validators.optional(
attrs.validators.instance_of((RectangleShape, SphereShape))
),
),
doc="Shape describing the surface. This parameter may be left unset "
"for situations in which the task of setting its value is delegated to "
"another component (*e.g.* an :class:`.Experiment` instance owning the "
"surface object); however, if it is still unset upon kernel dictionary "
"generation, the call to :meth:`.traverse` will raise a "
":class:`.TraversalError`.",
type=".RectangleShape or .SphereShape or None",
init_type=".RectangleShape or .SphereShape or dict, optional",
default=":class:`.RectangleShape <RectangleShape()>`",
)
@shape.validator
def _shape_validator(self, attribute, value):
if value is not None and value.bsdf is not None:
warnings.warn(
f"while validating '{attribute.name}': "
f"'{attribute.name}.bsdf' should be set to None; it will "
"be overridden during kernel dictionary generation",
OverriddenValueWarning,
)
bsdf: BSDF = documented(
attrs.field(
factory=LambertianBSDF,
converter=bsdf_factory.convert,
validator=attrs.validators.instance_of(BSDF),
),
doc="The reflection model attached to the surface.",
type=".BSDF",
init_type=".BSDF or dict, optional",
default=":class:`LambertianBSDF() <.LambertianBSDF>`",
)
[docs]
def update(self) -> None:
# Inherit docstring
# Fix BSDF ID
self.bsdf.id = self._bsdf_id
# Force BSDF referencing if the shape is defined
if self.shape is not None:
if isinstance(self.shape.bsdf, BSDF):
warnings.warn("Set BSDF will be overridden by surface BSDF settings.")
self.shape.bsdf = Ref(id=self._bsdf_id)
@property
def _shape_id(self):
"""
Mitsuba shape object identifier.
"""
return f"{self.id}_shape"
@property
def _bsdf_id(self):
"""
Mitsuba BSDF object identifier.
"""
return f"{self.id}_bsdf"
@property
def _template_bsdfs(self) -> dict:
kdict_template = traverse(self.bsdf)[0].data
result = {}
for key, param in kdict_template.items():
result[f"{self._bsdf_id}.{key}"] = param
return result
@property
def _template_shapes(self) -> dict:
kdict_template = traverse(self.shape)[0].data
result = {}
for key, param in kdict_template.items():
result[f"{self._shape_id}.{key}"] = param
return result
@property
def _params_bsdfs(self) -> dict:
umap_template = traverse(self.bsdf)[1].data
result = {}
for key, param in umap_template.items():
# If no lookup strategy is set, we must add one
if isinstance(param, UpdateParameter) and param.lookup_strategy is None:
param = attrs.evolve(
param,
lookup_strategy=TypeIdLookupStrategy(
mi.BSDF,
self._bsdf_id,
parameter_relpath=key,
),
)
result[f"{self._bsdf_id}.{key}"] = param
return result
@property
def _params_shapes(self) -> dict:
return {}
[docs]
def traverse(self, callback: SceneTraversal) -> None:
# Inherit docstring
if self.shape is None:
raise TraversalError(
"A 'BasicSurface' cannot be traversed if its 'shape' field is unset."
)
super().traverse(callback)
