trimesh.scene.transforms¶

Classes:

`EnforcedForest`(args, *kwargs)	A subclass of networkx.DiGraph that will raise an error if an edge is added which would make the DiGraph not a forest or tree.
`TransformForest`([base_frame])

Functions:

kwargs_to_matrix(**kwargs)

Turn a set of keyword arguments into a transformation matrix.

class trimesh.scene.transforms.EnforcedForest(*args, **kwargs)¶

Bases: networkx.classes.digraph.DiGraph

A subclass of networkx.DiGraph that will raise an error if an edge is added which would make the DiGraph not a forest or tree.

Methods:

`add_edge`(u, v, args, *kwargs)	Add an edge between u and v.
`add_edges_from`(args, *kwargs)	Add all the edges in ebunch_to_add.
`add_path`(args, *kwargs)
`disconnect_path`(path)
`get_edge_data_direction`(u, v)
`remove_edge`(args, *kwargs)	Remove the edge between u and v.
`remove_edges_from`(args, *kwargs)	Remove all edges specified in ebunch.
`shortest_path_undirected`(u, v)

add_edge(u, v, *args, **kwargs)¶

Add an edge between u and v.

The nodes u and v will be automatically added if they are not already in the graph.

Edge attributes can be specified with keywords or by directly accessing the edge’s attribute dictionary. See examples below.

Parameters

u (nodes) – Nodes can be, for example, strings or numbers. Nodes must be hashable (and not None) Python objects.
v (nodes) – Nodes can be, for example, strings or numbers. Nodes must be hashable (and not None) Python objects.
attr (keyword arguments, optional) – Edge data (or labels or objects) can be assigned using keyword arguments.

See also

add_edges_from(): add a collection of edges

Notes

Adding an edge that already exists updates the edge data.

Many NetworkX algorithms designed for weighted graphs use an edge attribute (by default weight) to hold a numerical value.

Examples

The following all add the edge e=(1, 2) to graph G:

>>> G = nx.Graph()  # or DiGraph, MultiGraph, MultiDiGraph, etc
>>> e = (1, 2)
>>> G.add_edge(1, 2)  # explicit two-node form
>>> G.add_edge(*e)  # single edge as tuple of two nodes
>>> G.add_edges_from([(1, 2)])  # add edges from iterable container

Associate data to edges using keywords:

>>> G.add_edge(1, 2, weight=3)
>>> G.add_edge(1, 3, weight=7, capacity=15, length=342.7)

For non-string attribute keys, use subscript notation.

>>> G.add_edge(1, 2)
>>> G[1][2].update({0: 5})
>>> G.edges[1, 2].update({0: 5})

add_edges_from(*args, **kwargs)¶

Add all the edges in ebunch_to_add.

Parameters

ebunch_to_add (container of edges) – Each edge given in the container will be added to the graph. The edges must be given as 2-tuples (u, v) or 3-tuples (u, v, d) where d is a dictionary containing edge data.
attr (keyword arguments, optional) – Edge data (or labels or objects) can be assigned using keyword arguments.

See also

add_edge(): add a single edge
add_weighted_edges_from(): convenient way to add weighted edges

Notes

Adding the same edge twice has no effect but any edge data will be updated when each duplicate edge is added.

Edge attributes specified in an ebunch take precedence over attributes specified via keyword arguments.

Examples

>>> G = nx.Graph()  # or DiGraph, MultiGraph, MultiDiGraph, etc
>>> G.add_edges_from([(0, 1), (1, 2)])  # using a list of edge tuples
>>> e = zip(range(0, 3), range(1, 4))
>>> G.add_edges_from(e)  # Add the path graph 0-1-2-3

Associate data to edges

>>> G.add_edges_from([(1, 2), (2, 3)], weight=3)
>>> G.add_edges_from([(3, 4), (1, 4)], label="WN2898")

add_path(*args, **kwargs)¶

disconnect_path(path)¶

get_edge_data_direction(u, v)¶

remove_edge(*args, **kwargs)¶

Remove the edge between u and v.

Parameters

u (nodes) – Remove the edge between nodes u and v.
v (nodes) – Remove the edge between nodes u and v.

Raises

NetworkXError – If there is not an edge between u and v.

See also

remove_edges_from(): remove a collection of edges

Examples

>>> G = nx.Graph()  # or DiGraph, etc
>>> nx.add_path(G, [0, 1, 2, 3])
>>> G.remove_edge(0, 1)
>>> e = (1, 2)
>>> G.remove_edge(*e)  # unpacks e from an edge tuple
>>> e = (2, 3, {"weight": 7})  # an edge with attribute data
>>> G.remove_edge(*e[:2])  # select first part of edge tuple

remove_edges_from(*args, **kwargs)¶

Remove all edges specified in ebunch.

Parameters

ebunch (list or container of edge tuples) –

Each edge given in the list or container will be removed from the graph. The edges can be:

2-tuples (u, v) edge between u and v.

3-tuples (u, v, k) where k is ignored.

See also

remove_edge(): remove a single edge

Notes

Will fail silently if an edge in ebunch is not in the graph.

Examples

>>> G = nx.path_graph(4)  # or DiGraph, MultiGraph, MultiDiGraph, etc
>>> ebunch = [(1, 2), (2, 3)]
>>> G.remove_edges_from(ebunch)

shortest_path_undirected(u, v)¶

class trimesh.scene.transforms.TransformForest(base_frame='world')¶

Bases: object

Methods:

`clear`()
`copy`()	Return a copy of the current TransformForest
`from_edgelist`(edges[, strict])	Load transform data from an edge list into the current scene graph.
`get`(frame_to[, frame_from])	Get the transform from one frame to another, assuming they are connected in the transform tree.
`load`(edgelist)	Load transform data from an edge list into the current scene graph.
`md5`()
`remove_geometries`(geometries)	Remove the reference for specified geometries from nodes without deleting the node.
`show`()	Plot the graph layout of the scene.
`to_edgelist`()	Export the current transforms as a list of edge tuples, with each tuple having the format: (node_a, node_b, {metadata})
`to_flattened`([base_frame])	Export the current transform graph as a flattened
`to_gltf`(scene)	Export a transforms as the ‘nodes’ section of a GLTF dict.
`to_svg`()
`update`(frame_to[, frame_from])	Update a transform in the tree.

Attributes:

`geometry_nodes`	Which nodes have this geometry?
`nodes`	A list of every node in the graph.
`nodes_geometry`	The nodes in the scene graph with geometry attached.

clear()¶

copy()¶

Return a copy of the current TransformForest

Returns: copied
Return type: TransformForest

from_edgelist(edges, strict=True)¶

Load transform data from an edge list into the current scene graph.

Parameters

edgelist ((n,) tuples) – (node_a, node_b, {key: value})
strict (bool) – If true, raise a ValueError when a malformed edge is passed in a tuple.

property geometry_nodes¶

Which nodes have this geometry?

Returns: geometry_nodes – Geometry name : (n,) node names
Return type: dict

get(frame_to, frame_from=None)¶

Get the transform from one frame to another, assuming they are connected in the transform tree.

If the frames are not connected a NetworkXNoPath error will be raised.

Parameters

frame_to (hashable) – Node name, usually a string (eg ‘mesh_0’)
frame_from (hashable) – Node name, usually a string (eg ‘world’). If None it will be set to self.base_frame

Returns

transform – Homogeneous transformation matrix

Return type

(4, 4) float

load(edgelist)¶

Load transform data from an edge list into the current scene graph.

Parameters: edgelist ((n,) tuples) – (node_a, node_b, {key: value})

md5()¶

property nodes¶

A list of every node in the graph.

Returns: nodes – All node names
Return type: (n,) array

property nodes_geometry¶

The nodes in the scene graph with geometry attached.

Returns: nodes_geometry – Node names which have geometry associated
Return type: (m,) array

remove_geometries(geometries)¶

Remove the reference for specified geometries from nodes without deleting the node.

Parameters: geometries (list or str) – Name of scene.geometry to dereference.

show()¶: Plot the graph layout of the scene.

to_edgelist()¶

Export the current transforms as a list of edge tuples, with each tuple having the format: (node_a, node_b, {metadata})

Returns: edgelist – Of edge tuples
Return type: (n,) list

to_flattened(base_frame=None)¶: Export the current transform graph as a flattened

to_gltf(scene)¶

Export a transforms as the ‘nodes’ section of a GLTF dict. Flattens tree.

Returns: gltf – with ‘nodes’ referencing a list of dicts
Return type: dict

to_svg()¶

update(frame_to, frame_from=None, **kwargs)¶

Update a transform in the tree.

Parameters

frame_from (hashable object) – Usually a string (eg ‘world’). If left as None it will be set to self.base_frame
frame_to (hashable object) – Usually a string (eg ‘mesh_0’)
matrix ((4,4) float) – Homogeneous transformation matrix
quaternion ((4,) float) – Quaternion ordered [w, x, y, z]
axis ((3,) float) – Axis of rotation
angle (float) – Angle of rotation, in radians
translation ((3,) float) – Distance to translate
geometry (hashable) – Geometry object name, e.g. ‘mesh_0’

trimesh.scene.transforms.kwargs_to_matrix(**kwargs)¶: Turn a set of keyword arguments into a transformation matrix.