forked from s_ranjbar/city_retrofit
1182 lines
37 KiB
Python
1182 lines
37 KiB
Python
"""
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creation.py
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--------------
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Create meshes from primitives, or with operations.
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"""
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from .base import Trimesh
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from .constants import log, tol
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from .geometry import faces_to_edges, align_vectors, plane_transform
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from . import util
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from . import grouping
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from . import triangles
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from . import transformations as tf
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import numpy as np
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import collections
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try:
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# shapely is a soft dependency
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from shapely.geometry import Polygon
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from shapely.wkb import loads as load_wkb
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except BaseException as E:
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# shapely will sometimes raise OSErrors
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# on import rather than just ImportError
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from . import exceptions
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# re-raise the exception when someone tries
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# to use the module that they don't have
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Polygon = exceptions.closure(E)
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load_wkb = exceptions.closure(E)
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def revolve(linestring,
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angle=None,
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sections=None,
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transform=None,
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**kwargs):
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"""
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Revolve a 2D line string around the 2D Y axis, with a result with
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the 2D Y axis pointing along the 3D Z axis.
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This function is intended to handle the complexity of indexing
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and is intended to be used to create all radially symmetric primitives,
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eventually including cylinders, annular cylinders, capsules, cones,
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and UV spheres.
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Note that if your linestring is closed, it needs to be counterclockwise
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if you would like face winding and normals facing outwards.
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Parameters
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-------------
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linestring : (n, 2) float
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Lines in 2D which will be revolved
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angle : None or float
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Angle in radians to revolve curve by
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sections : None or int
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Number of sections result should have
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If not specified default is 32 per revolution
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transform : None or (4, 4) float
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Transform to apply to mesh after construction
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**kwargs : dict
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Passed to Trimesh constructor
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Returns
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--------------
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revolved : Trimesh
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Mesh representing revolved result
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"""
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linestring = np.asanyarray(linestring, dtype=np.float64)
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# linestring must be ordered 2D points
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if len(linestring.shape) != 2 or linestring.shape[1] != 2:
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raise ValueError('linestring must be 2D!')
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if angle is None:
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# default to closing the revolution
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angle = np.pi * 2
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closed = True
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else:
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# check passed angle value
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closed = angle >= ((np.pi * 2) - 1e-8)
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if sections is None:
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# default to 32 sections for a full revolution
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sections = int(angle / (np.pi * 2) * 32)
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# change to face count
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sections += 1
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# create equally spaced angles
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theta = np.linspace(0, angle, sections)
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# 2D points around the revolution
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points = np.column_stack((np.cos(theta), np.sin(theta)))
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# how many points per slice
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per = len(linestring)
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# use the 2D X component as radius
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radius = linestring[:, 0]
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# use the 2D Y component as the height along revolution
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height = linestring[:, 1]
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# a lot of tiling to get our 3D vertices
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vertices = np.column_stack((
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np.tile(points, (1, per)).reshape((-1, 2)) *
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np.tile(radius, len(points)).reshape((-1, 1)),
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np.tile(height, len(points))))
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if closed:
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# should be a duplicate set of vertices
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assert np.allclose(vertices[:per],
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vertices[-per:])
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# chop off duplicate vertices
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vertices = vertices[:-per]
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if transform is not None:
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# apply transform to vertices
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vertices = tf.transform_points(vertices, transform)
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# how many slices of the pie
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slices = len(theta) - 1
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# start with a quad for every segment
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# this is a superset which will then be reduced
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quad = np.array([0, per, 1,
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1, per, per + 1])
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# stack the faces for a single slice of the revolution
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single = np.tile(quad, per).reshape((-1, 3))
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# `per` is basically the stride of the vertices
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single += np.tile(np.arange(per), (2, 1)).T.reshape((-1, 1))
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# remove any zero-area triangle
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# this covers many cases without having to think too much
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single = single[triangles.area(vertices[single]) > tol.merge]
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# how much to offset each slice
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# note arange multiplied by vertex stride
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# but tiled by the number of faces we actually have
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offset = np.tile(np.arange(slices) * per,
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(len(single), 1)).T.reshape((-1, 1))
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# stack a single slice into N slices
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stacked = np.tile(single.ravel(), slices).reshape((-1, 3))
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if tol.strict:
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# make sure we didn't screw up stacking operation
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assert np.allclose(stacked.reshape((-1, single.shape[0], 3)) - single, 0)
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# offset stacked and wrap vertices
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faces = (stacked + offset) % len(vertices)
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# create the mesh from our vertices and faces
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mesh = Trimesh(vertices=vertices, faces=faces)
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# strict checks run only in unit tests
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if (tol.strict and
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np.allclose(radius[[0, -1]], 0.0) or
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np.allclose(linestring[0], linestring[-1])):
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# if revolved curve starts and ends with zero radius
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# it should really be a valid volume, unless the sign
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# reversed on the input linestring
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assert mesh.is_volume
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return mesh
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def extrude_polygon(polygon,
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height,
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transform=None,
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triangle_args=None,
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**kwargs):
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"""
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Extrude a 2D shapely polygon into a 3D mesh
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Parameters
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----------
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polygon : shapely.geometry.Polygon
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2D geometry to extrude
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height : float
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Distance to extrude polygon along Z
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triangle_args : str or None
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Passed to triangle
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**kwargs:
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passed to Trimesh
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Returns
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----------
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mesh : trimesh.Trimesh
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Resulting extrusion as watertight body
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"""
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# create a triangulation from the polygon
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vertices, faces = triangulate_polygon(
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polygon, triangle_args=triangle_args, **kwargs)
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# extrude that triangulation along Z
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mesh = extrude_triangulation(vertices=vertices,
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faces=faces,
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height=height,
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transform=transform,
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**kwargs)
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return mesh
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def sweep_polygon(polygon,
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path,
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angles=None,
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**kwargs):
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"""
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Extrude a 2D shapely polygon into a 3D mesh along an
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arbitrary 3D path. Doesn't handle sharp curvature well.
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Parameters
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----------
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polygon : shapely.geometry.Polygon
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Profile to sweep along path
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path : (n, 3) float
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A path in 3D
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angles : (n,) float
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Optional rotation angle relative to prior vertex
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at each vertex
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Returns
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-------
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mesh : trimesh.Trimesh
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Geometry of result
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"""
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path = np.asanyarray(path, dtype=np.float64)
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if not util.is_shape(path, (-1, 3)):
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raise ValueError('Path must be (n, 3)!')
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# Extract 2D vertices and triangulation
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verts_2d = np.array(polygon.exterior)[:-1]
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base_verts_2d, faces_2d = triangulate_polygon(polygon, **kwargs)
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n = len(verts_2d)
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# Create basis for first planar polygon cap
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x, y, z = util.generate_basis(path[0] - path[1])
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tf_mat = np.ones((4, 4))
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tf_mat[:3, :3] = np.c_[x, y, z]
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tf_mat[:3, 3] = path[0]
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# Compute 3D locations of those vertices
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verts_3d = np.c_[verts_2d, np.zeros(n)]
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verts_3d = tf.transform_points(verts_3d, tf_mat)
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base_verts_3d = np.c_[base_verts_2d,
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np.zeros(len(base_verts_2d))]
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base_verts_3d = tf.transform_points(base_verts_3d,
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tf_mat)
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# keep matching sequence of vertices and 0- indexed faces
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vertices = [base_verts_3d]
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faces = [faces_2d]
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# Compute plane normals for each turn --
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# each turn induces a plane halfway between the two vectors
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v1s = util.unitize(path[1:-1] - path[:-2])
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v2s = util.unitize(path[1:-1] - path[2:])
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norms = np.cross(np.cross(v1s, v2s), v1s + v2s)
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norms[(norms == 0.0).all(1)] = v1s[(norms == 0.0).all(1)]
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norms = util.unitize(norms)
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final_v1 = util.unitize(path[-1] - path[-2])
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norms = np.vstack((norms, final_v1))
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v1s = np.vstack((v1s, final_v1))
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# Create all side walls by projecting the 3d vertices into each plane
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# in succession
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for i in range(len(norms)):
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verts_3d_prev = verts_3d
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# Rotate if needed
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if angles is not None:
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tf_mat = tf.rotation_matrix(angles[i],
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norms[i],
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path[i])
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verts_3d_prev = tf.transform_points(verts_3d_prev,
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tf_mat)
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# Project vertices onto plane in 3D
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ds = np.einsum('ij,j->i', (path[i + 1] - verts_3d_prev), norms[i])
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ds = ds / np.dot(v1s[i], norms[i])
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verts_3d_new = np.einsum('i,j->ij', ds, v1s[i]) + verts_3d_prev
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# Add to face and vertex lists
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new_faces = [[i + n, (i + 1) % n, i] for i in range(n)]
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new_faces.extend([[(i - 1) % n + n, i + n, i] for i in range(n)])
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# save faces and vertices into a sequence
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faces.append(np.array(new_faces))
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vertices.append(np.vstack((verts_3d, verts_3d_new)))
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verts_3d = verts_3d_new
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# do the main stack operation from a sequence to (n,3) arrays
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# doing one vstack provides a substantial speedup by
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# avoiding a bunch of temporary allocations
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vertices, faces = util.append_faces(vertices, faces)
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# Create final cap
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x, y, z = util.generate_basis(path[-1] - path[-2])
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vecs = verts_3d - path[-1]
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coords = np.c_[np.einsum('ij,j->i', vecs, x),
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np.einsum('ij,j->i', vecs, y)]
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base_verts_2d, faces_2d = triangulate_polygon(Polygon(coords))
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base_verts_3d = (np.einsum('i,j->ij', base_verts_2d[:, 0], x) +
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np.einsum('i,j->ij', base_verts_2d[:, 1], y)) + path[-1]
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faces = np.vstack((faces, faces_2d + len(vertices)))
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vertices = np.vstack((vertices, base_verts_3d))
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return Trimesh(vertices, faces)
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def extrude_triangulation(vertices,
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faces,
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height,
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transform=None,
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**kwargs):
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"""
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Extrude a 2D triangulation into a watertight mesh.
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Parameters
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----------
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vertices : (n, 2) float
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2D vertices
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faces : (m, 3) int
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Triangle indexes of vertices
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height : float
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Distance to extrude triangulation
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**kwargs : dict
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Passed to Trimesh constructor
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Returns
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---------
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mesh : trimesh.Trimesh
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Mesh created from extrusion
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"""
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vertices = np.asanyarray(vertices, dtype=np.float64)
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height = float(height)
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faces = np.asanyarray(faces, dtype=np.int64)
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if not util.is_shape(vertices, (-1, 2)):
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raise ValueError('Vertices must be (n,2)')
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if not util.is_shape(faces, (-1, 3)):
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raise ValueError('Faces must be (n,3)')
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if np.abs(height) < tol.merge:
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raise ValueError('Height must be nonzero!')
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# make sure triangulation winding is pointing up
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normal_test = triangles.normals(
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[util.stack_3D(vertices[faces[0]])])[0]
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normal_dot = np.dot(normal_test,
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[0.0, 0.0, np.sign(height)])[0]
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# make sure the triangulation is aligned with the sign of
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# the height we've been passed
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if normal_dot < 0.0:
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faces = np.fliplr(faces)
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# stack the (n,3) faces into (3*n, 2) edges
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edges = faces_to_edges(faces)
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edges_sorted = np.sort(edges, axis=1)
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# edges which only occur once are on the boundary of the polygon
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# since the triangulation may have subdivided the boundary of the
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# shapely polygon, we need to find it again
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edges_unique = grouping.group_rows(
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edges_sorted, require_count=1)
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# (n, 2, 2) set of line segments (positions, not references)
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boundary = vertices[edges[edges_unique]]
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# we are creating two vertical triangles for every 2D line segment
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# on the boundary of the 2D triangulation
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vertical = np.tile(boundary.reshape((-1, 2)), 2).reshape((-1, 2))
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vertical = np.column_stack((vertical,
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np.tile([0, height, 0, height],
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len(boundary))))
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vertical_faces = np.tile([3, 1, 2, 2, 1, 0],
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(len(boundary), 1))
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vertical_faces += np.arange(len(boundary)).reshape((-1, 1)) * 4
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vertical_faces = vertical_faces.reshape((-1, 3))
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# stack the (n,2) vertices with zeros to make them (n, 3)
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vertices_3D = util.stack_3D(vertices)
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# a sequence of zero- indexed faces, which will then be appended
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# with offsets to create the final mesh
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faces_seq = [faces[:, ::-1],
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faces.copy(),
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vertical_faces]
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vertices_seq = [vertices_3D,
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vertices_3D.copy() + [0.0, 0, height],
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vertical]
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# append sequences into flat nicely indexed arrays
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vertices, faces = util.append_faces(vertices_seq, faces_seq)
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if transform is not None:
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# apply transform here to avoid later bookkeeping
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vertices = tf.transform_points(
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vertices, transform)
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# if the transform flips the winding flip faces back
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# so that the normals will be facing outwards
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if tf.flips_winding(transform):
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# fliplr makes arrays non-contiguous
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faces = np.ascontiguousarray(np.fliplr(faces))
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# create mesh object with passed keywords
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mesh = Trimesh(vertices=vertices,
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faces=faces,
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**kwargs)
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# only check in strict mode (unit tests)
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if tol.strict:
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assert mesh.volume > 0.0
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return mesh
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def triangulate_polygon(polygon,
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triangle_args=None,
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**kwargs):
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"""
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Given a shapely polygon create a triangulation using a
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python interface to `triangle.c`:
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> `pip install triangle`
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Parameters
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---------
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polygon : Shapely.geometry.Polygon
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Polygon object to be triangulated
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triangle_args : str or None
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Passed to triangle.triangulate i.e: 'p', 'pq30'
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Returns
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--------------
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vertices : (n, 2) float
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Points in space
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faces : (n, 3) int
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Index of vertices that make up triangles
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"""
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# do the import here for soft requirement
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from triangle import triangulate
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# set default triangulation arguments if not specified
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if triangle_args is None:
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triangle_args = 'p'
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# turn the polygon in to vertices, segments, and hole points
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arg = _polygon_to_kwargs(polygon)
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# run the triangulation
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result = triangulate(arg, triangle_args)
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return result['vertices'], result['triangles']
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def _polygon_to_kwargs(polygon):
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"""
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Given a shapely polygon generate the data to pass to
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the triangle mesh generator
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Parameters
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---------
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polygon : Shapely.geometry.Polygon
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Input geometry
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Returns
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--------
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result : dict
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Has keys: vertices, segments, holes
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"""
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if not polygon.is_valid:
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raise ValueError('invalid shapely polygon passed!')
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def round_trip(start, length):
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"""
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Given a start index and length, create a series of (n, 2) edges which
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create a closed traversal.
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Examples
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---------
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start, length = 0, 3
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returns: [(0,1), (1,2), (2,0)]
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"""
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tiled = np.tile(np.arange(start, start + length).reshape((-1, 1)), 2)
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tiled = tiled.reshape(-1)[1:-1].reshape((-1, 2))
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tiled = np.vstack((tiled, [tiled[-1][-1], tiled[0][0]]))
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return tiled
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def add_boundary(boundary, start):
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# coords is an (n, 2) ordered list of points on the polygon boundary
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# the first and last points are the same, and there are no
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# guarantees on points not being duplicated (which will
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# later cause meshpy/triangle to shit a brick)
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coords = np.array(boundary.coords)
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# find indices points which occur only once, and sort them
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# to maintain order
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unique = np.sort(grouping.unique_rows(coords)[0])
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cleaned = coords[unique]
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vertices.append(cleaned)
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facets.append(round_trip(start, len(cleaned)))
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# holes require points inside the region of the hole, which we find
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# by creating a polygon from the cleaned boundary region, and then
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# using a representative point. You could do things like take the mean of
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# the points, but this is more robust (to things like concavity), if
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# slower.
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test = Polygon(cleaned)
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holes.append(np.array(test.representative_point().coords)[0])
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return len(cleaned)
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# sequence of (n,2) points in space
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vertices = collections.deque()
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# sequence of (n,2) indices of vertices
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facets = collections.deque()
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# list of (2) vertices in interior of hole regions
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holes = collections.deque()
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start = add_boundary(polygon.exterior, 0)
|
|
for interior in polygon.interiors:
|
|
try:
|
|
start += add_boundary(interior, start)
|
|
except BaseException:
|
|
log.warning('invalid interior, continuing')
|
|
continue
|
|
|
|
# create clean (n,2) float array of vertices
|
|
# and (m, 2) int array of facets
|
|
# by stacking the sequence of (p,2) arrays
|
|
vertices = np.vstack(vertices)
|
|
facets = np.vstack(facets).tolist()
|
|
|
|
# shapely polygons can include a Z component
|
|
# strip it out for the triangulation
|
|
if vertices.shape[1] == 3:
|
|
vertices = vertices[:, :2]
|
|
|
|
result = {'vertices': vertices,
|
|
'segments': facets}
|
|
# holes in meshpy lingo are a (h, 2) list of (x,y) points
|
|
# which are inside the region of the hole
|
|
# we added a hole for the exterior, which we slice away here
|
|
holes = np.array(holes)[1:]
|
|
if len(holes) > 0:
|
|
result['holes'] = holes
|
|
|
|
return result
|
|
|
|
|
|
def box(extents=None, transform=None, **kwargs):
|
|
"""
|
|
Return a cuboid.
|
|
|
|
Parameters
|
|
------------
|
|
extents : float, or (3,) float
|
|
Edge lengths
|
|
transform: (4, 4) float
|
|
Transformation matrix
|
|
**kwargs:
|
|
passed to Trimesh to create box
|
|
|
|
Returns
|
|
------------
|
|
geometry : trimesh.Trimesh
|
|
Mesh of a cuboid
|
|
"""
|
|
# vertices of the cube
|
|
vertices = [0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 1,
|
|
1, 1, 0, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1]
|
|
vertices = np.array(vertices,
|
|
order='C',
|
|
dtype=np.float64).reshape((-1, 3))
|
|
vertices -= 0.5
|
|
|
|
# resize cube based on passed extents
|
|
if extents is not None:
|
|
extents = np.asanyarray(extents, dtype=np.float64)
|
|
if extents.shape != (3,):
|
|
raise ValueError('Extents must be (3,)!')
|
|
vertices *= extents
|
|
|
|
# hardcoded face indices
|
|
faces = [1, 3, 0, 4, 1, 0, 0, 3, 2, 2, 4, 0, 1, 7, 3, 5, 1, 4,
|
|
5, 7, 1, 3, 7, 2, 6, 4, 2, 2, 7, 6, 6, 5, 4, 7, 5, 6]
|
|
faces = np.array(faces, order='C', dtype=np.int64).reshape((-1, 3))
|
|
|
|
face_normals = [-1, 0, 0, 0, -1, 0, -1, 0, 0, 0, 0, -1, 0, 0, 1, 0, -1,
|
|
0, 0, 0, 1, 0, 1, 0, 0, 0, -1, 0, 1, 0, 1, 0, 0, 1, 0, 0]
|
|
face_normals = np.asanyarray(face_normals,
|
|
order='C',
|
|
dtype=np.float64).reshape(-1, 3)
|
|
|
|
box = Trimesh(vertices=vertices,
|
|
faces=faces,
|
|
face_normals=face_normals,
|
|
process=False,
|
|
**kwargs)
|
|
|
|
# do the transform here to preserve face normals
|
|
if transform is not None:
|
|
box.apply_transform(transform)
|
|
|
|
return box
|
|
|
|
|
|
def icosahedron():
|
|
"""
|
|
Create an icosahedron, a 20 faced polyhedron.
|
|
|
|
Returns
|
|
-------------
|
|
ico : trimesh.Trimesh
|
|
Icosahederon centered at the origin.
|
|
"""
|
|
t = (1.0 + 5.0**.5) / 2.0
|
|
vertices = [-1, t, 0, 1, t, 0, -1, -t, 0, 1, -t, 0, 0, -1, t, 0, 1, t,
|
|
0, -1, -t, 0, 1, -t, t, 0, -1, t, 0, 1, -t, 0, -1, -t, 0, 1]
|
|
faces = [0, 11, 5, 0, 5, 1, 0, 1, 7, 0, 7, 10, 0, 10, 11,
|
|
1, 5, 9, 5, 11, 4, 11, 10, 2, 10, 7, 6, 7, 1, 8,
|
|
3, 9, 4, 3, 4, 2, 3, 2, 6, 3, 6, 8, 3, 8, 9,
|
|
4, 9, 5, 2, 4, 11, 6, 2, 10, 8, 6, 7, 9, 8, 1]
|
|
# scale vertices so each vertex radius is 1.0
|
|
vertices = np.reshape(vertices, (-1, 3)) / np.sqrt(2.0 + t)
|
|
faces = np.reshape(faces, (-1, 3))
|
|
mesh = Trimesh(vertices=vertices,
|
|
faces=faces,
|
|
process=False)
|
|
return mesh
|
|
|
|
|
|
def icosphere(subdivisions=3, radius=1.0, color=None):
|
|
"""
|
|
Create an isophere centered at the origin.
|
|
|
|
Parameters
|
|
----------
|
|
subdivisions : int
|
|
How many times to subdivide the mesh.
|
|
Note that the number of faces will grow as function of
|
|
4 ** subdivisions, so you probably want to keep this under ~5
|
|
radius : float
|
|
Desired radius of sphere
|
|
color: (3,) float or uint8
|
|
Desired color of sphere
|
|
|
|
Returns
|
|
---------
|
|
ico : trimesh.Trimesh
|
|
Meshed sphere
|
|
"""
|
|
def refine_spherical():
|
|
vectors = ico.vertices
|
|
scalar = (vectors ** 2).sum(axis=1)**.5
|
|
unit = vectors / scalar.reshape((-1, 1))
|
|
offset = radius - scalar
|
|
ico.vertices += unit * offset.reshape((-1, 1))
|
|
ico = icosahedron()
|
|
ico._validate = False
|
|
for j in range(subdivisions):
|
|
ico = ico.subdivide()
|
|
refine_spherical()
|
|
ico._validate = True
|
|
if color is not None:
|
|
ico.visual.face_colors = color
|
|
return ico
|
|
|
|
|
|
def uv_sphere(radius=1.0,
|
|
count=[32, 32],
|
|
theta=None,
|
|
phi=None):
|
|
"""
|
|
Create a UV sphere (latitude + longitude) centered at the
|
|
origin. Roughly one order of magnitude faster than an
|
|
icosphere but slightly uglier.
|
|
|
|
Parameters
|
|
----------
|
|
radius : float
|
|
Radius of sphere
|
|
count : (2,) int
|
|
Number of latitude and longitude lines
|
|
theta : (n,) float
|
|
Optional theta angles in radians
|
|
phi : (n,) float
|
|
Optional phi angles in radians
|
|
|
|
Returns
|
|
----------
|
|
mesh : trimesh.Trimesh
|
|
Mesh of UV sphere with specified parameters
|
|
"""
|
|
|
|
count = np.array(count, dtype=np.int)
|
|
count += np.mod(count, 2)
|
|
count[1] *= 2
|
|
|
|
# generate vertices on a sphere using spherical coordinates
|
|
if theta is None:
|
|
theta = np.linspace(0, np.pi, count[0])
|
|
if phi is None:
|
|
phi = np.linspace(0, np.pi * 2, count[1])[:-1]
|
|
spherical = np.dstack((np.tile(phi, (len(theta), 1)).T,
|
|
np.tile(theta, (len(phi), 1)))).reshape((-1, 2))
|
|
vertices = util.spherical_to_vector(spherical) * radius
|
|
|
|
# generate faces by creating a bunch of pie wedges
|
|
c = len(theta)
|
|
# a quad face as two triangles
|
|
pairs = np.array([[c, 0, 1],
|
|
[c + 1, c, 1]])
|
|
|
|
# increment both triangles in each quad face by the same offset
|
|
incrementor = np.tile(np.arange(c - 1), (2, 1)).T.reshape((-1, 1))
|
|
# create the faces for a single pie wedge of the sphere
|
|
strip = np.tile(pairs, (c - 1, 1))
|
|
strip += incrementor
|
|
# the first and last faces will be degenerate since the first
|
|
# and last vertex are identical in the two rows
|
|
strip = strip[1:-1]
|
|
|
|
# tile pie wedges into a sphere
|
|
faces = np.vstack([strip + (i * c) for i in range(len(phi))])
|
|
|
|
# poles are repeated in every strip, so a mask to merge them
|
|
mask = np.arange(len(vertices))
|
|
# the top pole are all the same vertex
|
|
mask[0::c] = 0
|
|
# the bottom pole are all the same vertex
|
|
mask[c - 1::c] = c - 1
|
|
|
|
# faces masked to remove the duplicated pole vertices
|
|
# and mod to wrap to fill in the last pie wedge
|
|
faces = mask[np.mod(faces, len(vertices))]
|
|
|
|
# we save a lot of time by not processing again
|
|
# since we did some bookkeeping mesh is watertight
|
|
mesh = Trimesh(vertices=vertices, faces=faces, process=False)
|
|
return mesh
|
|
|
|
|
|
def capsule(height=1.0,
|
|
radius=1.0,
|
|
count=[32, 32]):
|
|
"""
|
|
Create a mesh of a capsule, or a cylinder with hemispheric ends.
|
|
|
|
Parameters
|
|
----------
|
|
height : float
|
|
Center to center distance of two spheres
|
|
radius : float
|
|
Radius of the cylinder and hemispheres
|
|
count : (2,) int
|
|
Number of sections on latitude and longitude
|
|
|
|
Returns
|
|
----------
|
|
capsule : trimesh.Trimesh
|
|
Capsule geometry with:
|
|
- cylinder axis is along Z
|
|
- one hemisphere is centered at the origin
|
|
- other hemisphere is centered along the Z axis at height
|
|
"""
|
|
height = float(height)
|
|
radius = float(radius)
|
|
count = np.array(count, dtype=np.int)
|
|
count += np.mod(count, 2)
|
|
|
|
# create a theta where there is a double band around the equator
|
|
# so that we can offset the top and bottom of a sphere to
|
|
# get a nicely meshed capsule
|
|
theta = np.linspace(0, np.pi, count[0])
|
|
center = np.clip(np.arctan(tol.merge / radius),
|
|
tol.merge, np.inf)
|
|
offset = np.array([-center, center]) + (np.pi / 2)
|
|
theta = np.insert(theta,
|
|
int(len(theta) / 2),
|
|
offset)
|
|
|
|
capsule = uv_sphere(radius=radius,
|
|
count=count,
|
|
theta=theta)
|
|
|
|
top = capsule.vertices[:, 2] > tol.zero
|
|
capsule.vertices[top] += [0, 0, height]
|
|
|
|
return capsule
|
|
|
|
|
|
def cone(radius,
|
|
height,
|
|
sections=None,
|
|
transform=None,
|
|
**kwargs):
|
|
"""
|
|
Create a mesh of a cone along Z centered at the origin.
|
|
|
|
Parameters
|
|
----------
|
|
radius : float
|
|
The radius of the cylinder
|
|
height : float
|
|
The height of the cylinder
|
|
sections : int or None
|
|
How many pie wedges per revolution
|
|
transform : (4, 4) float or None
|
|
Transform to apply after creation
|
|
**kwargs : dict
|
|
Passed to Trimesh constructor
|
|
|
|
Returns
|
|
----------
|
|
cone: trimesh.Trimesh
|
|
Resulting mesh of a cone
|
|
"""
|
|
# create the 2D outline of a cone
|
|
linestring = [[0, 0],
|
|
[radius, 0],
|
|
[0, height]]
|
|
# revolve the profile to create a cone
|
|
cone = revolve(linestring=linestring,
|
|
sections=sections,
|
|
transform=transform,
|
|
**kwargs)
|
|
|
|
return cone
|
|
|
|
|
|
def cylinder(radius,
|
|
height,
|
|
sections=None,
|
|
segment=None,
|
|
transform=None,
|
|
**kwargs):
|
|
"""
|
|
Create a mesh of a cylinder along Z centered at the origin.
|
|
|
|
Parameters
|
|
----------
|
|
radius : float
|
|
The radius of the cylinder
|
|
height : float
|
|
The height of the cylinder
|
|
sections : int
|
|
How many pie wedges should the cylinder have
|
|
segment : (2, 3) float
|
|
Endpoints of axis, overrides transform and height
|
|
transform : (4, 4) float
|
|
Transform to apply
|
|
**kwargs:
|
|
passed to Trimesh to create cylinder
|
|
|
|
Returns
|
|
----------
|
|
cylinder: trimesh.Trimesh
|
|
Resulting mesh of a cylinder
|
|
"""
|
|
|
|
if segment is not None:
|
|
segment = np.asanyarray(segment, dtype=np.float64)
|
|
if segment.shape != (2, 3):
|
|
raise ValueError('segment must be 2 3D points!')
|
|
vector = segment[1] - segment[0]
|
|
# override height with segment length
|
|
height = np.linalg.norm(vector)
|
|
# point in middle of line
|
|
midpoint = segment[0] + (vector * 0.5)
|
|
# align Z with our desired direction
|
|
rotation = align_vectors([0, 0, 1], vector)
|
|
# translate to midpoint of segment
|
|
translation = tf.translation_matrix(midpoint)
|
|
# compound the rotation and translation
|
|
transform = np.dot(translation, rotation)
|
|
|
|
half = abs(float(height)) / 2.0
|
|
# create a profile to revolve
|
|
linestring = [[0, -half],
|
|
[radius, -half],
|
|
[radius, half],
|
|
[0, half]]
|
|
# generate cylinder through simple revolution
|
|
return revolve(linestring=linestring,
|
|
sections=sections,
|
|
transform=transform)
|
|
|
|
return cylinder
|
|
|
|
|
|
def annulus(r_min,
|
|
r_max,
|
|
height,
|
|
sections=None,
|
|
transform=None,
|
|
**kwargs):
|
|
"""
|
|
Create a mesh of an annular cylinder along Z centered at the origin.
|
|
|
|
Parameters
|
|
----------
|
|
r_min : float
|
|
The inner radius of the annular cylinder
|
|
r_max : float
|
|
The outer radius of the annular cylinder
|
|
height : float
|
|
The height of the annular cylinder
|
|
sections : int or None
|
|
How many pie wedges should the annular cylinder have
|
|
transform : (4, 4) float or None
|
|
Transform to apply to move result from the origin
|
|
**kwargs:
|
|
passed to Trimesh to create annulus
|
|
|
|
Returns
|
|
----------
|
|
annulus : trimesh.Trimesh
|
|
Mesh of annular cylinder
|
|
"""
|
|
r_min = abs(float(r_min))
|
|
# if center radius is zero this is a cylinder
|
|
if r_min < tol.merge:
|
|
return cylinder(radius=r_max,
|
|
height=height,
|
|
sections=sections,
|
|
transform=transform)
|
|
r_max = abs(float(r_max))
|
|
# we're going to center at XY plane so take half the height
|
|
half = abs(float(height)) / 2.0
|
|
# create counter-clockwise rectangle
|
|
linestring = [[r_min, -half],
|
|
[r_max, -half],
|
|
[r_max, half],
|
|
[r_min, half],
|
|
[r_min, -half]]
|
|
|
|
# revolve the curve
|
|
annulus = revolve(linestring=linestring,
|
|
sections=sections,
|
|
transform=transform,
|
|
**kwargs)
|
|
|
|
return annulus
|
|
|
|
|
|
def random_soup(face_count=100):
|
|
"""
|
|
Return random triangles as a Trimesh
|
|
|
|
Parameters
|
|
-----------
|
|
face_count : int
|
|
Number of faces desired in mesh
|
|
|
|
Returns
|
|
-----------
|
|
soup : trimesh.Trimesh
|
|
Geometry with face_count random faces
|
|
"""
|
|
vertices = np.random.random((face_count * 3, 3)) - 0.5
|
|
faces = np.arange(face_count * 3).reshape((-1, 3))
|
|
soup = Trimesh(vertices=vertices, faces=faces)
|
|
return soup
|
|
|
|
|
|
def axis(origin_size=0.04,
|
|
transform=None,
|
|
origin_color=None,
|
|
axis_radius=None,
|
|
axis_length=None):
|
|
"""
|
|
Return an XYZ axis marker as a Trimesh, which represents position
|
|
and orientation. If you set the origin size the other parameters
|
|
will be set relative to it.
|
|
|
|
Parameters
|
|
----------
|
|
transform : (4, 4) float
|
|
Transformation matrix
|
|
origin_size : float
|
|
Radius of sphere that represents the origin
|
|
origin_color : (3,) float or int, uint8 or float
|
|
Color of the origin
|
|
axis_radius : float
|
|
Radius of cylinder that represents x, y, z axis
|
|
axis_length: float
|
|
Length of cylinder that represents x, y, z axis
|
|
|
|
Returns
|
|
-------
|
|
marker : trimesh.Trimesh
|
|
Mesh geometry of axis indicators
|
|
"""
|
|
# the size of the ball representing the origin
|
|
origin_size = float(origin_size)
|
|
|
|
# set the transform and use origin-relative
|
|
# sized for other parameters if not specified
|
|
if transform is None:
|
|
transform = np.eye(4)
|
|
if origin_color is None:
|
|
origin_color = [255, 255, 255, 255]
|
|
if axis_radius is None:
|
|
axis_radius = origin_size / 5.0
|
|
if axis_length is None:
|
|
axis_length = origin_size * 10.0
|
|
|
|
# generate a ball for the origin
|
|
axis_origin = uv_sphere(radius=origin_size,
|
|
count=[10, 10])
|
|
axis_origin.apply_transform(transform)
|
|
|
|
# apply color to the origin ball
|
|
axis_origin.visual.face_colors = origin_color
|
|
|
|
# create the cylinder for the z-axis
|
|
translation = tf.translation_matrix(
|
|
[0, 0, axis_length / 2])
|
|
z_axis = cylinder(
|
|
radius=axis_radius,
|
|
height=axis_length,
|
|
transform=transform.dot(translation))
|
|
# XYZ->RGB, Z is blue
|
|
z_axis.visual.face_colors = [0, 0, 255]
|
|
|
|
# create the cylinder for the y-axis
|
|
translation = tf.translation_matrix(
|
|
[0, 0, axis_length / 2])
|
|
rotation = tf.rotation_matrix(np.radians(-90),
|
|
[1, 0, 0])
|
|
y_axis = cylinder(
|
|
radius=axis_radius,
|
|
height=axis_length,
|
|
transform=transform.dot(rotation).dot(translation))
|
|
# XYZ->RGB, Y is green
|
|
y_axis.visual.face_colors = [0, 255, 0]
|
|
|
|
# create the cylinder for the x-axis
|
|
translation = tf.translation_matrix(
|
|
[0, 0, axis_length / 2])
|
|
rotation = tf.rotation_matrix(np.radians(90),
|
|
[0, 1, 0])
|
|
x_axis = cylinder(
|
|
radius=axis_radius,
|
|
height=axis_length,
|
|
transform=transform.dot(rotation).dot(translation))
|
|
# XYZ->RGB, X is red
|
|
x_axis.visual.face_colors = [255, 0, 0]
|
|
|
|
# append the sphere and three cylinders
|
|
marker = util.concatenate([axis_origin,
|
|
x_axis,
|
|
y_axis,
|
|
z_axis])
|
|
return marker
|
|
|
|
|
|
def camera_marker(camera,
|
|
marker_height=0.4,
|
|
origin_size=None):
|
|
"""
|
|
Create a visual marker for a camera object, including an axis and FOV.
|
|
|
|
Parameters
|
|
---------------
|
|
camera : trimesh.scene.Camera
|
|
Camera object with FOV and transform defined
|
|
marker_height : float
|
|
How far along the camera Z should FOV indicators be
|
|
origin_size : float
|
|
Sphere radius of the origin (default: marker_height / 10.0)
|
|
|
|
Returns
|
|
------------
|
|
meshes : list
|
|
Contains Trimesh and Path3D objects which can be visualized
|
|
"""
|
|
|
|
# append the visualizations to an array
|
|
meshes = [axis(origin_size=marker_height / 10.0)]
|
|
|
|
try:
|
|
# path is a soft dependency
|
|
from .path.exchange.load import load_path
|
|
except ImportError:
|
|
# they probably don't have shapely installed
|
|
log.warning('unable to create FOV visualization!',
|
|
exc_info=True)
|
|
return meshes
|
|
|
|
# create sane origin size from marker height
|
|
if origin_size is None:
|
|
origin_size = marker_height / 10.0
|
|
|
|
# calculate vertices from camera FOV angles
|
|
x = marker_height * np.tan(np.deg2rad(camera.fov[0]) / 2.0)
|
|
y = marker_height * np.tan(np.deg2rad(camera.fov[1]) / 2.0)
|
|
z = marker_height
|
|
|
|
# combine the points into the vertices of an FOV visualization
|
|
points = np.array(
|
|
[(0, 0, 0),
|
|
(-x, -y, z),
|
|
(x, -y, z),
|
|
(x, y, z),
|
|
(-x, y, z)],
|
|
dtype=float)
|
|
|
|
# create line segments for the FOV visualization
|
|
# a segment from the origin to each bound of the FOV
|
|
segments = np.column_stack(
|
|
(np.zeros_like(points), points)).reshape(
|
|
(-1, 3))
|
|
|
|
# add a loop for the outside of the FOV then reshape
|
|
# the whole thing into multiple line segments
|
|
segments = np.vstack((segments,
|
|
points[[1, 2,
|
|
2, 3,
|
|
3, 4,
|
|
4, 1]])).reshape((-1, 2, 3))
|
|
|
|
# add a single Path3D object for all line segments
|
|
meshes.append(load_path(segments))
|
|
|
|
return meshes
|
|
|
|
|
|
def truncated_prisms(tris, origin=None, normal=None):
|
|
"""
|
|
Return a mesh consisting of multiple watertight prisms below
|
|
a list of triangles, truncated by a specified plane.
|
|
|
|
Parameters
|
|
-------------
|
|
triangles : (n, 3, 3) float
|
|
Triangles in space
|
|
origin : None or (3,) float
|
|
Origin of truncation plane
|
|
normal : None or (3,) float
|
|
Unit normal vector of truncation plane
|
|
|
|
Returns
|
|
-----------
|
|
mesh : trimesh.Trimesh
|
|
Triangular mesh
|
|
"""
|
|
if origin is None:
|
|
transform = np.eye(4)
|
|
else:
|
|
transform = plane_transform(origin=origin, normal=normal)
|
|
|
|
# transform the triangles to the specified plane
|
|
transformed = tf.transform_points(
|
|
tris.reshape((-1, 3)), transform).reshape((-1, 9))
|
|
|
|
# stack triangles such that every other one is repeated
|
|
vs = np.column_stack((transformed, transformed)).reshape((-1, 3, 3))
|
|
# set the Z value of the second triangle to zero
|
|
vs[1::2, :, 2] = 0
|
|
# reshape triangles to a flat array of points and transform back to original frame
|
|
vertices = tf.transform_points(
|
|
vs.reshape((-1, 3)), matrix=np.linalg.inv(transform))
|
|
|
|
# face indexes for a *single* truncated triangular prism
|
|
f = np.array([[2, 1, 0],
|
|
[3, 4, 5],
|
|
[0, 1, 4],
|
|
[1, 2, 5],
|
|
[2, 0, 3],
|
|
[4, 3, 0],
|
|
[5, 4, 1],
|
|
[3, 5, 2]])
|
|
# find the projection of each triangle with the normal vector
|
|
cross = np.dot([0, 0, 1], triangles.cross(transformed.reshape((-1, 3, 3))).T)
|
|
# stack faces into one prism per triangle
|
|
f_seq = np.tile(f, (len(transformed), 1)).reshape((-1, len(f), 3))
|
|
# if the normal of the triangle was positive flip the winding
|
|
f_seq[cross > 0] = np.fliplr(f)
|
|
# offset stacked faces to create correct indices
|
|
faces = (f_seq + (np.arange(len(f_seq)) * 6).reshape((-1, 1, 1))).reshape((-1, 3))
|
|
|
|
# create a mesh from the data
|
|
mesh = Trimesh(vertices=vertices, faces=faces, process=False)
|
|
|
|
return mesh
|