mayawalk¶

Collection of traversal algorithms for Autodesk Maya.

Content¶

Nodes functions

`mayawalk.parent`	Return the parent of `node`, if it has one, None otherwise.
`mayawalk.children`	Make an iterator returning children of `node`.
`mayawalk.siblings`	Make an iterator returning siblings of `node`.
`mayawalk.hierarchy`	Traverse `root` hierarchy.
`mayawalk.top_nodes`	Make an iterator returning the topmost nodes in `nodes`.
`mayawalk.connections`	Traverse `root` connections.
`mayawalk.connected`	Make an iterator returning nodes connected `node`.

Plugs functions

`mayawalk.plugs`	Make an iterator returning plugs of `node`.
`mayawalk.plug_parent`	Return `plug` parent, if it has one, None otherwise.
`mayawalk.plug_children`	Make an iterator returning children plugs of `plug`.
`mayawalk.plug_has_source`	Return True if `plug` has any source connection, False otherwise.
`mayawalk.plug_has_destinations`	Return True if `plug` has any destination connection, False otherwise.
`mayawalk.plug_has_connections`	Return True if `plug` has any source or destination connection.

Enums

mayawalk.ConnectionStatus

All connections status a plug can have.

Nodes functions¶

mayawalk.parent(node, include_world=False)¶

Return the parent of node, if it has one, None otherwise.

Parameters

node (MObject) – Dag node we want the parent of.
include_world (bool) – If parent is the world node, return it if True, return None if False. Defaults to False.

Returns

MObject, None

Example

>>> modifier = OpenMaya.MDagModifier()
>>> root = modifier.createNode('transform')        # root
>>> child = modifier.createNode('transform', root) # |- child
>>> modifier = modifier.doIt()
>>> parent(child) == root
True
>>> parent(root) == None
True

mayawalk.children(node, api_type=None)¶

Make an iterator returning children of node.

Parameters

node (MObject) – Dag node we want the children of.
api_type (int, None) – Only yields nodes of specified Mfn constant type. Defaults to None (same as filtering by MFn.kDagNode).

Yields

MObject – children of node.

Example

>>> modifier = OpenMaya.MDagModifier()
>>> root = modifier.createNode('transform')         # root
>>> shape = modifier.createNode('nurbsCurve', root) # |- shape
>>> group = modifier.createNode('transform', root)  # |- group
>>> modifier = modifier.doIt()
>>> list(children(root)) == [shape, group]
True
>>> list(children(root, api_type=OpenMaya.MFn.kNurbsCurve)) == [shape]
True

mayawalk.siblings(node, api_type=None)¶

Make an iterator returning siblings of node.

Parameters

node (MObject) – Dag node we want the siblings of.
api_type (int, None) – Only yields nodes of specified Mfn constant type. Defaults to None (same as filtering by MFn.kDagNode).

Yields

MObject – Nodes at the same hierarchical level (same parent) than node.

Example

>>> modifier = OpenMaya.MDagModifier()
>>> root = modifier.createNode('transform')        # root
>>> node = modifier.createNode('transform', root)  # |- node
>>> group = modifier.createNode('transform', root) # |- group
>>> joint = modifier.createNode('joint', root)     # |- joint
>>> modifier = modifier.doIt()
>>> list(siblings(node, api_type=OpenMaya.MFn.kJoint)) == [joint]
True
>>> list(siblings(node)) == [group, joint]
True

mayawalk.hierarchy(root, stoppers=None, api_type=None, depth_first=False, upstream=False)¶

Traverse root hierarchy.

Info:: root is included as the first element in the returned iterator.

Parameters

root (MObject) – Starting dag node.
stoppers (list[MObject], None) – Don’t iterate past these nodes. They are still yielded and won’t break the iteration. Defaults to None.
api_type (int, None) – Only yields nodes of specified Mfn constant type. Defaults to None (same as filtering by MFn.kDagNode).
depth_first (bool) – Traversal algorithm. Use depth-first search if True, breadth-first search if False. Defaults to False.
downstream (bool) – Traversal direction. Go upstream (parents) if True, downstream (children) if False. The depth_first param has no effect when going upstream. Defaults to False.

Yields

MObject – Nodes in root (included) hierarchy.

Example

>>> modifier = OpenMaya.MDagModifier()
>>> root = modifier.createNode('transform')           # root
>>> node_a = modifier.createNode('transform', root)   # |- node_a
>>> shape = modifier.createNode('nurbsCurve', node_a) #    |- shape
>>> node_b = modifier.createNode('joint', root)       # |- node_b
>>> modifier = modifier.doIt()
>>> list(hierarchy(root)) == [root, node_a, node_b, shape]
True
>>> list(hierarchy(shape, upstream=True)) == [shape, node_a, root]
True

mayawalk.top_nodes(nodes, sparse=False)¶

Make an iterator returning the topmost nodes in nodes.

A top node is a node whose parent(s) is not in the input nodes list.

Parameters

nodes (list[MObject]) – A list of dag nodes objects.
sparse (bool) – If you want to find the top nodes in a sparse hierarchy. If False, only check the first parent of each node against nodes. If True, check all parents in the upstream hierarchy of each nodes against nodes.

Yields

MObject – Members of nodes list whose parent is not in nodes.

Example

>>> modifier = OpenMaya.MDagModifier()
>>> node_a = modifier.createNode('transform')          # node_a
>>> node_b = modifier.createNode('transform', node_a)  # |- node_b
>>> node_c = modifier.createNode('transform', node_b)  #    |- node_c
>>> modifier = modifier.doIt()
>>> list(top_nodes([node_b, node_c])) == [node_b]
True
>>> list(top_nodes([node_a, node_c], sparse=True)) == [node_a]
True

mayawalk.connections(root, stoppers=None, api_type=None, depth_first=False, upstream=False)¶

Traverse root connections.

Info:: root is included as the first element in the returned iterator.

Parameters

root (MObject) – Starting dependency node.
stoppers (list[MObject], None) – Don’t iterate past these nodes. They are still yielded and won’t break the iteration. Defaults to None.
api_type (int, None) – Only yields nodes of specified Mfn constant type. Defaults to None (same as filtering by MFn.kDagNode).
depth_first (bool) – Traversal algorithm. Use depth-first search if True, breadth-first search if False. Defaults to False.
downstream (bool) – Traversal direction. Go upstream (sources, left) if True, downstream (destinations, right) if False. Defaults to False.

Yields

MObject – Nodes connected directly and indirectly to root (included).

Example

>>> modifier = OpenMaya.MDagModifier()
>>> node_a = modifier.createNode('transform')
>>> node_b = modifier.createNode('transform')
>>> node_c = modifier.createNode('transform')
>>> modifier = modifier.doIt()
>>> plug_a = OpenMaya.MFnDagNode(node_a).findPlug('tx', False)
>>> plug_b = OpenMaya.MFnDagNode(node_b).findPlug('tx', False)
>>> plug_c = OpenMaya.MFnDagNode(node_c).findPlug('tx', False)
>>> modifier = modifier.connect(plug_a, plug_b).doIt()
>>> modifier = modifier.connect(plug_b, plug_c).doIt()
>>> # node_a.tx >> node_b.tx >> node_c.tx
>>> list(connections(node_a)) == [node_a, node_b, node_c]
True
>>> list(connections(node_c, upstream=True)) == [node_c, node_b, node_a]
True
>>> list(connections(node_a, stoppers=[node_b])) == [node_a, node_b]
True

mayawalk.connected(node, sources=True, destinations=True)¶

Make an iterator returning nodes connected node.

Parameters

node (MObject) – Node to find the connections of.
sources (bool) – Include node sources. Defaults to True.
destinations (bool) – Include node destinations. Defaults to True.

Yields

MObject – Nodes directly connected to node.

Example

>>> modifier = OpenMaya.MDagModifier()
>>> src = modifier.createNode('transform')
>>> dst = modifier.createNode('transform')
>>> modifier = modifier.doIt()
>>> modifier = modifier.connect(
...     OpenMaya.MFnDagNode(src).findPlug('tx', False),
...     OpenMaya.MFnDagNode(dst).findPlug('tx', False)).doIt()
>>> # src.tx >> dst.tx
>>> list(connected(src, sources=False, destinations=True)) == [dst]
True
>>> list(connected(dst, sources=True, destinations=False)) == [src]
True

Plugs functions¶

mayawalk.plugs(node, connection=None)¶

Make an iterator returning plugs of node.

Parameters

node (MObject) – Node we want the plugs of.
connection (int, None) – If specified, only yields nodes of this ConnectionStatus. Defaults to None.

Yields

MPlug – Plugs of node.

mayawalk.plug_parent(plug)¶

Return plug parent, if it has one, None otherwise.

Parameters: plug (MPlug) – Plug we want the parent of.
Returns: MPlug, None

Example

>>> modifier = OpenMaya.MDagModifier()
>>> node = OpenMaya.MFnDagNode(modifier.createNode('transform'))
>>> modifier = modifier.doIt()
>>> translate = node.findPlug('translate', False)
>>> translate_x = node.findPlug('translateX', False)
>>> plug_parent(translate) == None
True
>>> plug_parent(translate_x) == translate
True

mayawalk.plug_children(plug, reverse=False, physical_indexes=False)¶

Make an iterator returning children plugs of plug.

Iterator might be empty if plug is neither an array nor a compound, or is a non-physical plug (for example animCurveUU.keyTanOutX).

Parameters

plug (MPlug) – The plug we want chilren of.
physical_indexes (bool) – If mplug is an array, return the physical indexes if True, the logical indexes if False. Default to False.
reverse (bool) – Iter children in the correct order if False (X, Y, Z or 0, 1, 2) or in reverse order if True (Z, Y, X or 2, 1, 0). Default to False.

Yields

MPlug – Children mplugs of plug

Raises

IndexError – Unknown error when trying to get a child plug.

Example

>>> modifier = OpenMaya.MDagModifier()
>>> node = OpenMaya.MFnDagNode(modifier.createNode('transform'))
>>> modifier = modifier.doIt()
>>> translate = node.findPlug('t', False)
>>> children = [node.findPlug('t' + axis, False) for axis in 'xyz']
>>> list(plug_children(translate)) == children
True
>>> children.reverse()
>>> list(plug_children(translate, reverse=True)) == children
True

mayawalk.plug_has_source(plug, nested=False)¶

Return True if plug has any source connection, False otherwise.

Parameters: nested (bool) – If True, extend the check to all children in plug hierarchy.
Returns: bool

mayawalk.plug_has_destinations(plug, nested=False)¶

Return True if plug has any destination connection, False otherwise.

Parameters: nested (bool) – If True, extend the check to all children in plug hierarchy.
Returns: bool

mayawalk.plug_has_connections(plug, nested=False)¶

Return True if plug has any source or destination connection.

Convenience function that run both plug_has_source and plug_has_destinations.

Parameters: nested (bool) – If True, extend the check to all children in plug hierarchy.
Returns: bool

Enums¶

class mayawalk.ConnectionStatus¶

All connections status a plug can have. Enum class.

classmethod has_status(plug, connection)¶

Parameters

plug (MPlug) – Plug to check.
connection (int) – ConnectionStatus constant.

Returns

bool – True if plug has connection status, False otherwise.

kConnected = 1¶: Has any connection.

kConnectedDestinations = 3¶: Has destination(s) / is a source.

kConnectedSources = 2¶: Has a source / is a destination.

kDisconnected = 4¶: Has no connection.

kDisconnectedDestinations = 6¶: Has no destinations / is not a source.

kDisconnectedSources = 5¶: Has no source / is not a destination.