trimesh.path.polygons¶
Functions:
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Given an edge list of indices and associated vertices representing lines, generate a list of polygons. |
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Given a list of shapely polygons with only exteriors, find which curves represent the exterior shell or root curve and which represent holes which penetrate the exterior. |
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Given a shapely polygon, find the approximate medial axis using a voronoi diagram of evenly spaced points on the boundary of the polygon. |
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Given a sequence of connected points turn them into valid shapely Polygon objects. |
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Plot a shapely polygon using matplotlib. |
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Return a vector containing values representitive of a particular polygon. |
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Find the oriented bounding box of a Shapely polygon. |
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For a Polygon object return the diagonal length of the AABB. |
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Find the OBBs for a list of shapely.geometry.Polygons |
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Project a mesh onto a plane and then extract the polygon that outlines the mesh projection on that plane. |
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Generate a random polygon with a maximum number of sides and approximate radius. |
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Given a shapely.geometry.Polygon, attempt to return a valid version of the polygon through buffering tricks. |
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Return a version of a polygon with boundaries resampled to a specified resolution. |
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Use rejection sampling to generate random points inside a polygon. |
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Stack the boundaries of a polygon into a single (n, 2) list of vertices. |
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Transform a polygon by a a 2D homogeneous transform. |
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trimesh.path.polygons.edges_to_polygons(edges, vertices)¶ Given an edge list of indices and associated vertices representing lines, generate a list of polygons.
- Parameters
edges ((n, 2) int) – Indexes of vertices which represent lines
vertices ((m, 2) float) – Vertices in 2D space
- Returns
polygons – Polygon objects with interiors
- Return type
(p,) shapely.geometry.Polygon
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trimesh.path.polygons.enclosure_tree(polygons)¶ Given a list of shapely polygons with only exteriors, find which curves represent the exterior shell or root curve and which represent holes which penetrate the exterior.
This is done with an R-tree for rough overlap detection, and then exact polygon queries for a final result.
- Parameters
polygons ((n,) shapely.geometry.Polygon) – Polygons which only have exteriors and may overlap
- Returns
roots ((m,) int) – Index of polygons which are root
contains (networkx.DiGraph) – Edges indicate a polygon is contained by another polygon
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trimesh.path.polygons.medial_axis(polygon, resolution=None, clip=None)¶ Given a shapely polygon, find the approximate medial axis using a voronoi diagram of evenly spaced points on the boundary of the polygon.
- Parameters
polygon (shapely.geometry.Polygon) – The source geometry
resolution (float) – Distance between each sample on the polygon boundary
clip (None, or (2,) int) – Clip sample count to min of clip[0] and max of clip[1]
- Returns
edges ((n, 2) int) – Vertex indices representing line segments on the polygon’s medial axis
vertices ((m, 2) float) – Vertex positions in space
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trimesh.path.polygons.paths_to_polygons(paths, scale=None)¶ Given a sequence of connected points turn them into valid shapely Polygon objects.
- Parameters
paths ((n,) sequence) – Of (m, 2) float closed paths
scale (float) – Approximate scale of drawing for precision
- Returns
polys – Filled with Polygon or None
- Return type
(p,) list
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trimesh.path.polygons.plot_polygon(polygon, show=True, **kwargs)¶ Plot a shapely polygon using matplotlib.
- Parameters
polygon (shapely.geometry.Polygon) – Polygon to be plotted
show (bool) – If True will display immediately
**kwargs – Passed to plt.plot
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trimesh.path.polygons.polygon_hash(polygon)¶ Return a vector containing values representitive of a particular polygon.
- Parameters
polygon (shapely.geometry.Polygon) – Input geometry
- Returns
hashed – Representitive values representing input polygon
- Return type
(6), float
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trimesh.path.polygons.polygon_obb(polygon)¶ Find the oriented bounding box of a Shapely polygon.
The OBB is always aligned with an edge of the convex hull of the polygon.
- Parameters
polygons (shapely.geometry.Polygon) – Input geometry
- Returns
transform ((3, 3) float) – Transformation matrix which will move input polygon from its original position to the first quadrant where the AABB is the OBB
extents ((2,) float) – Extents of transformed polygon
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trimesh.path.polygons.polygon_scale(polygon)¶ For a Polygon object return the diagonal length of the AABB.
- Parameters
polygon (shapely.geometry.Polygon) – Source geometry
- Returns
scale – Length of AABB diagonal
- Return type
float
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trimesh.path.polygons.polygons_obb(polygons)¶ Find the OBBs for a list of shapely.geometry.Polygons
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trimesh.path.polygons.projected(mesh, normal, origin=None, pad=1e-05, tol_dot=0.01, max_regions=200)¶ Project a mesh onto a plane and then extract the polygon that outlines the mesh projection on that plane.
- Parameters
mesh (trimesh.Trimesh) – Source geometry
check (bool) – If True make sure is flat
normal ((3,) float) – Normal to extract flat pattern along
origin (None or (3,) float) – Origin of plane to project mesh onto
pad (float) – Proportion to pad polygons by before unioning and then de-padding result by to avoid zero-width gaps.
tol_dot (float) – Tolerance for discarding on-edge triangles.
max_regions (int) – Raise an exception if the mesh has more than this number of disconnected regions to fail quickly before unioning.
- Returns
projected – Outline of source mesh
- Return type
shapely.geometry.Polygon
- Raises
ValueError – If max_regions is exceeded
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trimesh.path.polygons.random_polygon(segments=8, radius=1.0)¶ Generate a random polygon with a maximum number of sides and approximate radius.
- Parameters
segments (int) – The maximum number of sides the random polygon will have
radius (float) – The approximate radius of the polygon desired
- Returns
polygon – Geometry object with random exterior and no interiors.
- Return type
shapely.geometry.Polygon
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trimesh.path.polygons.repair_invalid(polygon, scale=None, rtol=0.5)¶ Given a shapely.geometry.Polygon, attempt to return a valid version of the polygon through buffering tricks.
- Parameters
polygon (shapely.geometry.Polygon) – Source geometry
rtol (float) – How close does a perimeter have to be
scale (float or None) – For numerical precision reference
- Returns
repaired – Repaired polygon
- Return type
shapely.geometry.Polygon
- Raises
ValueError – If polygon can’t be repaired
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trimesh.path.polygons.resample_boundaries(polygon, resolution, clip=None)¶ Return a version of a polygon with boundaries resampled to a specified resolution.
- Parameters
polygon (shapely.geometry.Polygon) – Source geometry
resolution (float) – Desired distance between points on boundary
clip ((2,) int) – Upper and lower bounds to clip number of samples to avoid exploding count
- Returns
kwargs – Keyword args for a Polygon constructor Polygon(**kwargs)
- Return type
dict
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trimesh.path.polygons.sample(polygon, count, factor=1.5, max_iter=10)¶ Use rejection sampling to generate random points inside a polygon.
- Parameters
polygon (shapely.geometry.Polygon) – Polygon that will contain points
count (int) – Number of points to return
factor (float) – How many points to test per loop
max_iter (int) – Maximum number of intersection checks is: > count * factor * max_iter
- Returns
hit – Random points inside polygon where n <= count
- Return type
(n, 2) float
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trimesh.path.polygons.stack_boundaries(boundaries)¶ Stack the boundaries of a polygon into a single (n, 2) list of vertices.
- Parameters
boundaries (dict) – With keys ‘shell’, ‘holes’
- Returns
stacked – Stacked vertices
- Return type
(n, 2) float
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trimesh.path.polygons.transform_polygon(polygon, matrix)¶ Transform a polygon by a a 2D homogeneous transform.
- Parameters
polygon (shapely.geometry.Polygon) – 2D polygon to be transformed.
matrix ((3, 3) float) – 2D homogeneous transformation.
- Returns
result – Polygon transformed by matrix.
- Return type
shapely.geometry.Polygon