"""Module containing the Shape class and its subclasses, which represent shapes of Objects"""
from abc import ABC, abstractmethod
import numpy
import shapely
import trimesh
from trimesh.transformations import (
concatenate_matrices,
quaternion_matrix,
translation_matrix,
)
from scenic.core.type_support import toOrientation
from scenic.core.utils import cached_property, findMeshInteriorPoint, unifyMesh
from scenic.core.vectors import Orientation
###################################################################################################
# Abstract Classes and Utilities
###################################################################################################
[docs]
class Shape(ABC):
"""An abstract base class for Scenic shapes.
Represents a physical shape in Scenic. Does not encode position or orientation,
which are handled by the `Region` class. Does contain dimension information, which
is used as a default value by any `Object` with this shape and can be overwritten.
If dimensions and scale are both specified the dimensions are first set by dimensions,
and then scaled by scale.
Args:
dimensions: The raw (before scaling) dimensions of the shape.
scale: Scales all the dimensions of the shape by a multiplicative factor.
"""
def __init__(self, dimensions, scale):
# Store values
self.raw_dimensions = dimensions
self.scale = scale
self.dimensions = tuple(dim * self.scale for dim in self.raw_dimensions)
self.width = self.dimensions[0]
self.length = self.dimensions[1]
self.height = self.dimensions[2]
for dim, name in zip(self.dimensions, ("width", "length", "height")):
if dim <= 0:
raise ValueError(f"{name} of shape must be positive")
@cached_property
def containsCenter(self):
"""Whether or not this object contains its central point"""
pq = trimesh.proximity.ProximityQuery(self.mesh)
region_distance = pq.signed_distance([(0, 0, 0)])[0]
return region_distance > 0
@property
@abstractmethod
def mesh(self):
pass
@property
@abstractmethod
def isConvex(self):
pass
@cached_property
def _circumradius(self):
return numpy.max(numpy.linalg.norm(self.mesh.vertices, axis=1))
@cached_property
def _interiorPoint(self):
return findMeshInteriorPoint(self.mesh)
@cached_property
def _multipoint(self):
return shapely.multipoints(self.mesh.vertices)
###################################################################################################
# 3D Shape Classes
###################################################################################################
[docs]
class MeshShape(Shape):
"""A Shape subclass defined by a `trimesh.base.Trimesh` object.
The mesh passed must be a `trimesh.base.Trimesh` object that represents a well defined
volume (i.e. the ``is_volume`` property must be true), meaning the mesh must be watertight,
have consistent winding and have outward facing normals.
Args:
mesh: A mesh object.
dimensions: The raw (before scaling) dimensions of the shape. If dimensions
and scale are both specified the dimensions are first set by dimensions, and then
scaled by scale.
scale: Scales all the dimensions of the shape by a multiplicative factor.
If dimensions and scale are both specified the dimensions are first set by dimensions,
and then scaled by scale.
initial_rotation: A 3-tuple containing the yaw, pitch, and roll respectively to apply when loading
the mesh. Note the initial_rotation must be fixed.
"""
def __init__(self, mesh, dimensions=None, scale=1, initial_rotation=None):
# Ensure the mesh is watertight so volume is well defined
if not mesh.is_volume:
raise ValueError(
"A MeshShape cannot be defined with a mesh that does not have a well defined volume."
" Consider using scenic.core.utils.repairMesh."
)
# Copy mesh and center vertices around origin
self._mesh = mesh.copy()
self._mesh.vertices -= self._mesh.bounding_box.center_mass
# If rotation is provided, apply rotation
if initial_rotation is not None:
rotation = toOrientation(initial_rotation)
rotation_matrix = quaternion_matrix(
(rotation.w, rotation.x, rotation.y, rotation.z)
)
self._mesh.apply_transform(rotation_matrix)
# If dimensions are not specified, infer them.
if dimensions is None:
dimensions = list(self._mesh.extents)
# Scale mesh to unit size
scale_vals = numpy.array(self._mesh.extents)
scale_matrix = numpy.eye(4)
scale_matrix[:3, :3] /= scale_vals
self._mesh.apply_transform(scale_matrix)
super().__init__(dimensions, scale)
[docs]
@classmethod
def fromFile(cls, path, unify=True, **kwargs):
"""Load a mesh shape from a file, attempting to infer filetype and compression.
For example: "foo.obj.bz2" is assumed to be a compressed .obj file.
"foo.obj" is assumed to be an uncompressed .obj file. "foo" is an
unknown filetype, so unless a filetype is provided an exception will be raised.
Args:
path (str): Path to the file to import.
filetype (str): Filetype of file to be imported. This will be inferred if not provided.
The filetype must be one compatible with `trimesh.load`.
compressed (bool): Whether or not this file is compressed (with bz2). This will be inferred
if not provided.
binary (bool): Whether or not to open the file as a binary file.
unify (bool): Whether or not to attempt to unify this mesh.
kwargs: Additional arguments to the MeshShape initializer.
"""
mesh = trimesh.load(path, force="mesh")
if not mesh.is_volume:
raise ValueError(
"A MeshShape cannot be defined with a mesh that does not have a well defined volume."
" Consider using scenic.core.utils.repairMesh."
)
if unify:
mesh = unifyMesh(mesh, verbose=True)
return cls(mesh, **kwargs)
@property
def mesh(self):
return self._mesh
@cached_property
def isConvex(self):
return self._mesh.is_convex
def __getstate__(self):
state = self.__dict__.copy()
state["_mesh"] = self._mesh.copy()
return state
[docs]
class BoxShape(MeshShape):
"""A box shape with all dimensions 1 by default."""
def __init__(self, dimensions=(1, 1, 1), scale=1, initial_rotation=None):
super().__init__(
trimesh.creation.box((1, 1, 1)), dimensions, scale, initial_rotation
)
[docs]
class CylinderShape(MeshShape):
"""A cylinder shape with all dimensions 1 by default."""
def __init__(self, dimensions=(1, 1, 1), scale=1, initial_rotation=None, sections=24):
super().__init__(
trimesh.creation.cylinder(radius=0.5, height=1, sections=sections),
dimensions,
scale,
initial_rotation,
)
self.sections = sections
[docs]
class ConeShape(MeshShape):
"""A cone shape with all dimensions 1 by default."""
def __init__(self, dimensions=(1, 1, 1), scale=1, initial_rotation=None):
super().__init__(
trimesh.creation.cone(radius=0.5, height=1),
dimensions,
scale,
initial_rotation,
)
[docs]
class SpheroidShape(MeshShape):
"""A spheroid shape with all dimensions 1 by default."""
def __init__(self, dimensions=(1, 1, 1), scale=1, initial_rotation=None):
super().__init__(
trimesh.creation.icosphere(radius=1), dimensions, scale, initial_rotation
)