trimesh.scene.transforms module¶

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.
`add_path`(args, *kwargs)	Add a path.
`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 providing a dictionary with key/value pairs. See examples below.

Parameters

v (u,) – Nodes can be, for example, strings or numbers. Nodes must be hashable (and not None) Python objects.
attr_dict (dictionary, optional (default= no attributes)) – Dictionary of edge attributes. Key/value pairs will update existing data associated with the edge.
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 as the edge weight a numerical value assigned to a keyword which by default is ‘weight’.

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)

add_edges_from(*args, **kwargs)¶

Add all the edges in ebunch.

Parameters

ebunch (container of edges) – Each edge given in the container will be added to the graph. The edges must be given as as 2-tuples (u,v) or 3-tuples (u,v,d) where d is a dictionary containing edge data.
attr_dict (dictionary, optional (default= no attributes)) – Dictionary of edge attributes. Key/value pairs will update existing data associated with each edge.
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 edges take precedence over attributes specified generally.

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)¶

Add a path.

Parameters

nodes (iterable container) – A container of nodes. A path will be constructed from the nodes (in order) and added to the graph.
attr (keyword arguments, optional (default= no attributes)) – Attributes to add to every edge in path.

See also

add_star(), add_cycle()

Examples

>>> G=nx.Graph()   # or DiGraph, MultiGraph, MultiDiGraph, etc
>>> G.add_path([0,1,2,3])
>>> G.add_path([10,11,12],weight=7)

disconnect_path(path)¶

get_edge_data_direction(u, v)¶

remove_edge(*args, **kwargs)¶

Remove the edge between u and v.

Parameters: v (u,) – 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
>>> G.add_path([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.Graph()   # or DiGraph, MultiGraph, MultiDiGraph, etc
>>> G.add_path([0,1,2,3])
>>> 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`()
`show`()	Plot the graph layout of the scene.
`to_edgelist`()	Export the current transforms as a list of
`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

`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.

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

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.