from __future__ import annotations
import logging
import typing as t
import warnings
import attrs
import mitsuba as mi
from tqdm.auto import tqdm
from ._kernel_dict import UpdateMapTemplate
from .._config import ProgressLevel, config
from ..attrs import documented, parse_docs
from ..contexts import KernelContext
from ..rng import SeedState, root_seed_state
logger = logging.getLogger(__name__)
# ------------------------------------------------------------------------------
# Parameter lookup strategies
# ------------------------------------------------------------------------------
[docs]@parse_docs
@attrs.frozen
class TypeIdLookupStrategy:
"""
This parameter ID lookup strategy searches for a Mitsuba type and object ID
match.
Instances are callables which take, as argument, the current node during
a Mitsuba scene tree traversal and, optionally, its path in the Mitsuba
scene tree. If the lookup succeeds, the full parameter path is returned.
"""
node_type: type = documented(
attrs.field(validator=attrs.validators.instance_of(type)),
doc="Type of the node which will be looked up.",
type="type",
)
node_id: str = documented(
attrs.field(validator=attrs.validators.instance_of(str)),
doc="ID of the node which will be looked up.",
type="str",
)
parameter_relpath: str = documented(
attrs.field(validator=attrs.validators.instance_of(str)),
doc="Parameter path relative to its parent object.",
type="str",
)
def __call__(self, node, node_path: str | None = None) -> str | None:
if isinstance(node, self.node_type) and node.id() == self.node_id:
prefix = f"{node_path}." if node_path is not None else ""
return f"{prefix}{self.parameter_relpath}"
else:
return None
# ------------------------------------------------------------------------------
# Mitsuba scene traversal
# ------------------------------------------------------------------------------
[docs]@parse_docs
@attrs.define
class MitsubaObjectWrapper:
"""
This container aggregates a Mitsuba object, its associated parameters and a
set of updaters that can be used to modify the scene parameters.
See Also
--------
:func:`mi_traverse`
"""
obj: mi.Object = documented(
attrs.field(repr=lambda x: "Scene[...]" if isinstance(x, mi.Scene) else str(x)),
doc="Mitsuba object.",
type="mitsuba.Object",
)
parameters: mi.SceneParameters | None = documented(
attrs.field(
default=None,
repr=lambda x: "SceneParameters[...]"
if x.__class__.__name__ == "SceneParameters"
else str(None),
),
doc="Mitsuba scene parameter map.",
type="mitsuba.SceneParameters",
init_type="mitsuba.SceneParameters, optional",
default="None",
)
umap_template: UpdateMapTemplate | None = documented(
attrs.field(
default=None,
repr=lambda x: "UpdateMapTemplate[...]"
if isinstance(x, UpdateMapTemplate)
else str(x),
),
doc="An update map template, which can be rendered and used to update "
"Mitsuba scene parameters depending on context information.",
type=".UpdateMapTemplate",
init_type=".UpdateMapTemplate, optional",
default="None",
)
[docs] def drop_parameters(self) -> None:
"""
Reduce the size of the scene parameter table :attr:`.parameters` by
only keeping elements whose keys are listed in the parameter update
map template :attr:`.umap_template`. For parameters associated with a
lookup protocol, the looked up parameter ID is checked and used.
"""
if self.umap_template is not None:
keys = []
for name, param in self.umap_template.items():
if param.lookup_strategy is not None:
if param.parameter_id is not None:
keys.append(param.parameter_id)
else:
warnings.warn(
f"Parameter '{name}' has a lookup strategy but the "
"associated parameter ID is undefined; was a "
"parameter lookup performed during the Mitsuba "
"scene traversal?"
)
else:
keys.append(name)
self.parameters.keep(keys)
[docs]def mi_traverse(
obj: mi.Object,
umap_template: UpdateMapTemplate | None = None,
) -> MitsubaObjectWrapper:
"""
Traverse a node of the Mitsuba scene graph and return a container holding
the Mitsuba scene, its parameter map and an updated parameter update map.
Parameters
----------
obj : mitsuba.Object
Mitsuba scene graph node to be traversed.
umap_template : .UpdateMapTemplate, optional
An additional update map template which is to be updated during
traversal. This is used to perform parameter lookup during traversal.
Returns
-------
MitsubaObjectWrapper
A container holding the traversed object, the corresponding parameter
map and the parameter update map (if any).
Notes
-----
This is a reimplementation of the :func:`mitsuba.traverse` function.
"""
umap_template = (
UpdateMapTemplate(data=umap_template.data.copy())
if umap_template is not None
else UpdateMapTemplate()
)
lookups = {
k: v
for k, v in umap_template.items()
if v.parameter_id is None and v.lookup_strategy is not None
}
class SceneTraversal(mi.TraversalCallback):
def __init__(
self,
node,
parent=None,
properties=None,
hierarchy=None,
prefixes=None,
name=None,
depth=0,
flags=+mi.ParamFlags.Differentiable,
):
mi.TraversalCallback.__init__(self)
self.properties = dict() if properties is None else properties
self.hierarchy = dict() if hierarchy is None else hierarchy
self.prefixes = set() if prefixes is None else prefixes
if name is not None:
ctr, name_len = 1, len(name)
while name in self.prefixes:
name = "%s_%i" % (name[:name_len], ctr)
ctr += 1
self.prefixes.add(name)
self.name = name
self.node = node
self.depth = depth
self.hierarchy[node] = (parent, depth)
self.flags = flags
# Try and recover a parameter ID from this node
for name, uparam in list(lookups.items()):
lookup_result = uparam.lookup_strategy(self.node, self.name)
if lookup_result is not None:
uparam.parameter_id = lookup_result
del lookups[
name
] # Remove successful lookups to accelerate future searches
def put_parameter(self, name, ptr, flags, cpptype=None):
name = name if self.name is None else self.name + "." + name
flags = self.flags | flags
# Non-differentiable parameters shouldn't be flagged as discontinuous
if (flags & mi.ParamFlags.NonDifferentiable) != 0:
flags = flags & ~mi.ParamFlags.Discontinuous
self.properties[name] = (ptr, cpptype, self.node, self.flags | flags)
def put_object(self, name, node, flags):
if node is None or node in self.hierarchy:
return
cb = SceneTraversal(
node=node,
parent=self.node,
properties=self.properties,
hierarchy=self.hierarchy,
prefixes=self.prefixes,
name=name if self.name is None else f"{self.name}.{name}",
depth=self.depth + 1,
flags=self.flags | flags,
)
node.traverse(cb)
cb = SceneTraversal(obj)
obj.traverse(cb)
# Check if there are unsuccessful lookups
if lookups:
warnings.warn(
"There were unsuccessful Mitsuba scene parameter lookups: "
f"{list(lookups.keys())}"
)
return MitsubaObjectWrapper(
obj=obj,
parameters=mi.SceneParameters(cb.properties, cb.hierarchy),
umap_template=umap_template,
)
# ------------------------------------------------------------------------------
# Mitsuba scene render
# ------------------------------------------------------------------------------
[docs]def mi_render(
mi_scene: MitsubaObjectWrapper,
ctxs: list[KernelContext],
sensors: None | int | list[int] = None,
spp: int = 0,
seed_state: SeedState | None = None,
) -> dict[t.Any, mi.Bitmap]:
"""
Render a Mitsuba scene multiple times given specified contexts and sensor
indices.
Parameters
----------
mi_scene : .MitsubaObjectWrapper
Mitsuba scene to render.
ctxs : list of :class:`.KernelContext`
List of contexts used to generate the parameter update table at each
iteration.
sensors : int or list of int, optional
Sensor indices to render. If ``None`` (default), all sensors are
rendered.
spp : int, optional, default: 0
Number of samples per pixel. If set to 0 (default), the value set in the
original scene definition takes precedence.
seed_state : .SeedState, optional
Seed state used to generate seeds to initialize Mitsuba's RNG at
each run. If unset, Eradiate's root seed state is used.
Returns
-------
dict
A nested dictionary mapping context and sensor indices to rendered
bitmaps.
Notes
-----
This function wraps sequential calls to :func:`mitsuba.render`.
"""
if seed_state is None:
logger.debug("Using default RNG seed generator")
seed_state = root_seed_state
results = {}
# Loop on contexts
with tqdm(
initial=0,
total=len(ctxs),
unit_scale=1.0,
leave=True,
bar_format="{desc}{n:g}/{total:g}|{bar}| {elapsed}, ETA={remaining}",
disable=(config.progress < ProgressLevel.SPECTRAL_LOOP) or len(ctxs) <= 1,
) as pbar:
for ctx in ctxs:
pbar.set_description(
f"Eradiate [{ctx.index_formatted}]",
refresh=True,
)
logger.debug("Updating Mitsuba scene parameters")
mi_scene.parameters.update(mi_scene.umap_template.render(ctx))
if sensors is None:
mi_sensors = [
(i, sensor) for i, sensor in enumerate(mi_scene.obj.sensors())
]
else:
if isinstance(sensors, int):
sensors = [sensors]
mi_sensors = [(i, mi_scene.obj.sensors()[i]) for i in sensors]
# Loop on sensors
for i_sensor, mi_sensor in mi_sensors:
# Render sensor
seed = int(seed_state.next())
logger.debug(
'Running Mitsuba for sensor "%s" with seed value %s',
mi_sensor.id(),
seed,
)
mi.render(mi_scene.obj, sensor=i_sensor, seed=seed, spp=spp)
# Store result in a new Bitmap object
siah = ctx.si.as_hashable
if siah not in results:
results[siah] = {}
results[siah][mi_sensor.id()] = mi.Bitmap(mi_sensor.film().bitmap())
pbar.update()
return results
