from __future__ import annotations
import typing as t
import attrs
import mitsuba as mi
import numpy as np
import pint
import pinttr
from pinttr.util import ensure_units
from ._core import ShapeNode
from ..bsdfs import BSDF
from ..core import BoundingBox
from ...attrs import documented, parse_docs
from ...contexts import KernelContext
from ...units import unit_context_config as ucc
from ...units import unit_context_kernel as uck
from ...units import unit_registry as ureg
def _edges_converter(x):
# Basic unit conversion and array reshaping
length_units = ucc.get("length")
x = np.reshape(
pinttr.util.ensure_units(x, default_units=length_units).m_as(length_units),
(-1,),
)
# Broadcast if relevant
if len(x) == 1:
x = np.full((3,), x[0])
return x * length_units
[docs]
@parse_docs
@attrs.define(eq=False, slots=False)
class CuboidShape(ShapeNode):
"""
Cuboid shape [``cuboid``].
This shape represents an axis-aligned cuboid parametrized by the length of
its edges and the coordinates of its central point.
"""
center: pint.Quantity = documented(
pinttr.field(factory=lambda: [0, 0, 0], units=ucc.deferred("length")),
doc="Coordinates of the centre of the cube. "
"Unit-enabled field (default: ``ucc['length']``).",
type="quantity",
init_type="quantity or array-like, optional",
default="[0, 0, 0]",
)
edges: pint.Quantity = documented(
pinttr.field(
factory=lambda: [1, 1, 1],
converter=_edges_converter,
units=ucc.deferred("length"),
),
doc="Lengths of the edges of the cuboid. "
"Unit-enabled field (default: ``ucc['length]``).",
type="quantity",
init_type="quantity or array-like",
default="[1, 1, 1]",
)
@property
def bbox(self) -> BoundingBox:
# Inherit docstring
return BoundingBox(
self.center - 0.5 * self.edges, self.center + 0.5 * self.edges
)
[docs]
def contains(
self, p: np.typing.ArrayLike, strict: bool = False
) -> t.Sequence[bool]:
"""
Test whether a point lies within the cuboid.
Parameters
----------
p : quantity or array-like
An array of shape (3,) (resp. (N, 3)) representing one (resp. N)
points. If a unitless value is passed, it is interpreted as
``ucc['length']``.
strict : bool
If ``True``, comparison is done using strict inequalities (<, >).
Returns
-------
result : array of bool or bool
``True`` iff ``p`` in within the cuboid.
"""
node_min = self.center - 0.5 * self.edges
node_max = self.center + 0.5 * self.edges
p = np.atleast_2d(ensure_units(p, ucc.get("length")))
cmp = (
np.logical_and(p > node_min, p < node_max)
if strict
else np.logical_and(p >= node_min, p <= node_max)
)
return np.all(cmp, axis=1)
def eval_to_world(self, ctx: KernelContext | None = None) -> mi.ScalarTransform4f:
kwargs = ctx.kwargs.get(self.id, {}) if ctx is not None else {}
if "to_world" in kwargs:
return kwargs["to_world"]
else:
length_units = uck.get("length")
converters = {field.name: field.converter for field in self.__attrs_attrs__}
edges = (
converters["edges"](kwargs["edges"])
if "edges" in kwargs
else self.edges
)
center = (
converters["center"](kwargs["center"])
if "center" in kwargs
else self.center
)
return mi.ScalarTransform4f.translate(
center.m_as(length_units)
) @ mi.ScalarTransform4f.scale(0.5 * edges.m_as(length_units))
@property
def template(self) -> dict:
length_units = uck.get("length")
return {
"type": "cube",
"to_world": mi.ScalarTransform4f.translate(self.center.m_as(length_units))
[docs]
@ mi.ScalarTransform4f.scale(0.5 * self.edges.m_as(length_units)),
}
@classmethod
def atmosphere(
cls,
top: pint.Quantity = 100.0 * ureg.km,
bottom: pint.Quantity = 0.0 * ureg.km,
bottom_offset: pint.Quantity = None,
width: pint.Quantity = 100.0 * ureg.km,
bsdf: BSDF | None = None,
) -> CuboidShape:
"""
This class method constructor provides a simplified parametrization of
the cuboid shape better suited for the definition of the atmosphere when
configuring the one-dimensional model with a plane parallel geometry.
Parameters
----------
top : quantity, optional, default: 100 km
Top of atmosphere altitude. If a unitless value is passed, it is
interpreted as ucc['length'].
bottom : quantity, optional, default: 0 km
Ground altitude. If a unitless value is passed, it is interpreted as
``ucc['length']``.
bottom_offset : quantity, optional
Additional offset by which the cuboid with be extended to avoid an
exact match of its bottom face and the shape representing the
surface. If left unset, defaults to a negative offset of 1 % of
the atmosphere's height, *i.e.*
:math:`- 0.01 \\times (\\mathtt{top} - \\mathtt{bottom})`.
If a unitless value is passed, it is interpreted as ``ucc['length']``.
width : quantity, optional, default: 100 km
Length of the horizontal edges of the cuboid.
If a unitless value is passed, it is interpreted as ``ucc['length']``.
bsdf : BSDF or dict, optional, default: None
A BSDF specification, forwarded to the main constructor.
Returns
-------
CuboidShape
A cuboid shape which can be used as the atmosphere in a plane
parallel geometry.
"""
top = pinttr.util.ensure_units(top, default_units=ucc.get("length"))
bottom = pinttr.util.ensure_units(bottom, default_units=ucc.get("length"))
width = pinttr.util.ensure_units(width, default_units=ucc.get("length"))
if bottom_offset is None:
bottom_offset = -0.01 * (top - bottom)
else:
bottom_offset = pinttr.util.ensure_units(
bottom_offset, default_units=ucc.get("length")
)
length_units = top.units
center_z = 0.5 * (top + bottom + bottom_offset).m_as(length_units)
edge_x = np.squeeze(width.m_as(length_units))
edge_y = np.squeeze(width.m_as(length_units))
edge_z = np.squeeze((top - bottom - bottom_offset).m_as(length_units))
return cls(
center=[0.0, 0.0, center_z] * length_units,
edges=[edge_x, edge_y, edge_z] * length_units,
bsdf=bsdf,
)
