Node

class omni.graph.core.Node

Bases: pybind11_object

An element of execution within a graph, containing attributes and connected to other nodes

Methods

`__init__`(args, *kwargs)
`clear_old_compute_messages`(self)	Clears all compute messages logged for the node prior to its most recent evaluation.
`create_attribute`(self, attributeName, ...)	Creates an attribute with the specified name, type, and port type and returns success state.
`deregister_on_connected_callback`(self, callback)	De-registers the on_connected callback to be invoked when attributes connect.
`deregister_on_disconnected_callback`(self, ...)	De-registers the on_disconnected callback to be invoked when attributes disconnect.
`deregister_on_path_changed_callback`(self, ...)	Deregisters the on_path_changed callback to be invoked when anything changes in the stage.
`get_attribute`(self, name)	Given the name of an attribute returns an attribute object to it.
`get_attribute_exists`(self, name)	Given an attribute name, returns whether this attribute exists or not.
`get_attributes`(self)	Returns the list of attributes on this node.
`get_backing_bucket_id`(self)	This method was internal, and is now obsolete: it does not function anymore.
`get_compound_graph_instance`(self)	Returns a handle to the associated sub-graph, if the given node is a compound node.
`get_compute_count`(self)	Returns the number of instances on which this node's computation has been invoked.
`get_compute_messages`(self, severity)	Returns a list of the compute messages currently logged for the node at a specific severity.
`get_compute_vectorized_count`(self)	Returns the number of vectorized segments on which this node's computation has been invoked.
`get_event_stream`(self)	Get the event stream the node uses for notification of changes.
`get_graph`(self)	Get the graph to which this node belongs
`get_graph_instance_id`(self[, instance])	param instance an index that identify the graph instance for which a unique ID is requested
`get_handle`(self)	Get an opaque handle to the node
`get_node_type`(self)	Gets the node type of this node
`get_prim_path`(self)	Returns the path to the prim currently backing the node.
`get_type_name`(self)	Get the node type name
`get_wrapped_graph`(self)	Get the graph wrapped by this node
`increment_compute_count`(self)	Increments the node's compute counter.
`is_backed_by_usd`(self)	Check if the node is back by USD or not
`is_compound_node`(self)	Returns whether this node is a compound node.
`is_disabled`(self)	Check if the node is currently disabled
`is_valid`(self)	Check the validity of the node
`log_compute_message`(self, severity, message)	Logs a compute message of a given severity for the node.
`node_id`(self)	Returns a unique identifier value for this node.
`register_on_connected_callback`(self, callback)	Registers a callback to be invoked when the node has attributes connected.
`register_on_disconnected_callback`(self, callback)	Registers a callback to be invoked when the node has attributes disconnected.
`register_on_path_changed_callback`(self, callback)	Registers a callback to be invoked when a path changes in the stage.
`remove_attribute`(self, attributeName)	Removes an attribute with the specified name and type and returns success state.
`request_compute`(self)	Requests a compute of this node
`resolve_coupled_attributes`(self, attributesArray)	Resolves attribute types given a set of attributes which are fully type coupled.
`resolve_partially_coupled_attributes`(self, ...)	Resolves attribute types given a set of attributes, that can have differing tuple counts and/or array depth, and differing but convertible base data type.
`set_compute_incomplete`(self)	Informs the system that compute is incomplete for this frame.
`set_disabled`(self, disabled)	Sets whether the node is disabled or not.

__init__(*args, **kwargs)

clear_old_compute_messages(self: omni.graph.core._omni_graph_core.Node) → int

Clears all compute messages logged for the node prior to its most recent evaluation. Messages logged during the most recent evaluation remain untouched.

Normally this will be called during graph evaluation so it is of little use unless you’re writing your own evaluation manager.

Returns: The number of messages that were deleted.
Return type: int

create_attribute(self: omni.graph.core._omni_graph_core.Node, attributeName: str, attributeType: omni::graph::core::Py_Type, portType: omni.graph.core._omni_graph_core.AttributePortType = <AttributePortType.ATTRIBUTE_PORT_TYPE_INPUT: 0>, value: object = None, extendedType: omni.graph.core._omni_graph_core.ExtendedAttributeType = <ExtendedAttributeType.EXTENDED_ATTR_TYPE_REGULAR: 0>, unionTypes: str = '') → bool

Creates an attribute with the specified name, type, and port type and returns success state.

Parameters

attributeName (str) – Name of the attribute.
attributeType (omni.graph.core.Type) – Type of the attribute.
portType (omni.graph.core.AttributePortType) – The port type of the attribute, defaults to omni.graph.core.AttributePortType.ATTRIBUTE_PORT_TYPE_INPUT
value (Any) – The initial value to set on the attribute, default is None
extendedType (omni.graph.core.ExtendedAttributeType) – The extended type of the attribute, defaults to omni.graph.core.ExtendedAttributeType.EXTENDED_ATTR_TYPE_REGULAR
unionTypes (str) – Comma-separated list of union types if the extended type is omni.graph.core.ExtendedAttributeType.EXTENDED_ATTR_TYPE_UNION, defaults to empty string for non-union types.

Returns

True if the creation was successful, else False

Return type

bool

deregister_on_connected_callback(self: omni.graph.core._omni_graph_core.Node, callback: int) → None

De-registers the on_connected callback to be invoked when attributes connect.

Parameters: callback (callable) – The handle that was returned during the register_on_connected_callback call

deregister_on_disconnected_callback(self: omni.graph.core._omni_graph_core.Node, callback: int) → None

De-registers the on_disconnected callback to be invoked when attributes disconnect.

Parameters: callback (callable) – The handle that was returned during the register_on_disconnected_callback call

deregister_on_path_changed_callback(self: omni.graph.core._omni_graph_core.Node, callback: int) → None

Deregisters the on_path_changed callback to be invoked when anything changes in the stage. [DEPRECATED]

Parameters: callback (callable) – The handle that was returned during the register_on_path_changed_callback call

get_attribute(self: omni.graph.core._omni_graph_core.Node, name: str) → omni.graph.core._omni_graph_core.Attribute

Given the name of an attribute returns an attribute object to it.

Parameters: name (str) – The name of the attribute
Returns: Attribute with the given name, or None if it does not exist on the node
Return type: omni.graph.core.Attribute

get_attribute_exists(self: omni.graph.core._omni_graph_core.Node, name: str) → bool

Given an attribute name, returns whether this attribute exists or not.

Parameters: name (str) – The name of the attribute
Returns: True if the attribute exists on this node, else False
Return type: bool

get_attributes(self: omni.graph.core._omni_graph_core.Node) → List[omni.graph.core._omni_graph_core.Attribute]: Returns the list of attributes on this node.

get_backing_bucket_id(self: omni.graph.core._omni_graph_core.Node) → omni::fabric::BucketId: This method was internal, and is now obsolete: it does not function anymore. In order to write back to USD, you can directly use the USD API.

get_compound_graph_instance(self: omni.graph.core._omni_graph_core.Node) → omni::graph::core::Py_Graph

Returns a handle to the associated sub-graph, if the given node is a compound node.

Returns: The subgraph
Return type: omni.graph.core.Graph

get_compute_count(self: omni.graph.core._omni_graph_core.Node) → int

Returns the number of instances on which this node’s computation has been invoked. The counter has a limited range and will eventually roll over to 0, so a higher count cannot be assumed to represent a more recent compute than an older one.

Returns: Number of instances this node’s computation has been invoked since the counter last rolled over to 0.
Return type: int

get_compute_messages(self: omni.graph.core._omni_graph_core.Node, severity: omni::graph::core::ogn::Severity) → List[str]

Returns a list of the compute messages currently logged for the node at a specific severity.

Parameters: severity (omni.graph.core.Severity) – Severity level of the message.
Returns: The list of messages, may be empty.
Return type: list[str]

get_compute_vectorized_count(self: omni.graph.core._omni_graph_core.Node) → int

Returns the number of vectorized segments on which this node’s computation has been invoked. The counter has a limited range and will eventually roll over to 0, so a higher count cannot be assumed to represent a more recent compute than an older one.

Returns: Number of vectorized segments on which this node’s computation has been invoked since the counter last rolled over to 0.
Return type: int

get_event_stream(self: omni.graph.core._omni_graph_core.Node) → carb.events._events.IEventStream

Get the event stream the node uses for notification of changes.

Returns: Event stream to monitor for node changes
Return type: carb.events.IEventStream

get_graph(self: omni.graph.core._omni_graph_core.Node) → omni::graph::core::Py_Graph

Get the graph to which this node belongs

Returns: Graph associated with the current node. The returned graph will be invalid if the node is not valid.
Return type: omni.graph.core.Graph

get_graph_instance_id(self: omni.graph.core._omni_graph_core.Node, instance: int = 18446744073709551614) → str

Parameters

instance (int) – an index that identify the graph instance for which a unique ID is requested
instantiated (Be aware that even if not) –
graph (the authoring) –

Returns

A unique name that identifies the graph for the requested index.

get_handle(self: omni.graph.core._omni_graph_core.Node) → int

Get an opaque handle to the node

Returns: a unique handle to the node
Return type: int

get_node_type(self: omni.graph.core._omni_graph_core.Node) → omni::graph::core::Py_NodeType

Gets the node type of this node

Returns: The node type from which this node was created.
Return type: omni.graph.core.NodeType

get_prim_path(self: omni.graph.core._omni_graph_core.Node) → str: Returns the path to the prim currently backing the node.

get_type_name(self: omni.graph.core._omni_graph_core.Node) → str

Get the node type name

Returns: The type name of the node.
Return type: str

get_wrapped_graph(self: omni.graph.core._omni_graph_core.Node) → omni::graph::core::Py_Graph

Get the graph wrapped by this node

Returns: The graph wrapped by the current node, if any. The returned graph will be invalid if the node does not wrap a graph or is invalid.
Return type: omni.graph.core.Graph

increment_compute_count(self: omni.graph.core._omni_graph_core.Node) → int

Increments the node’s compute counter. This method is provided primarily for debugging and experimental uses and should not normally be used by end-users.

Returns: The new compute counter. This may be zero if the counter has just rolled over.
Return type: int

is_backed_by_usd(self: omni.graph.core._omni_graph_core.Node) → bool

Check if the node is back by USD or not

Returns: True if the current node is by an USD prim on the stage.
Return type: bool

is_compound_node(self: omni.graph.core._omni_graph_core.Node) → bool

Returns whether this node is a compound node. A compound node is a node that has a node type that is defined by an OmniGraph.

Returns: True if this node is a compound node, False otherwise.
Return type: bool

is_disabled(self: omni.graph.core._omni_graph_core.Node) → bool

Check if the node is currently disabled

Returns: True if the node is disabled.
Return type: bool

is_valid(self: omni.graph.core._omni_graph_core.Node) → bool

Check the validity of the node

Returns: True if the node is valid.
Return type: bool

log_compute_message(self: omni.graph.core._omni_graph_core.Node, severity: omni::graph::core::ogn::Severity, message: str) → bool

Logs a compute message of a given severity for the node.

This method is intended to be used from within the compute() method of a node to alert the user to any problems or issues with the node’s most recent evaluation. They are accumulated until the next successful evaluation at which point they are cleared.

If duplicate messages are logged, with the same severity level, only one is stored.

Parameters

severity (omni.graph.core.Severity) – Severity level of the message.
message (str) – The message.

Returns

True if the message has already been logged, else False

Return type

bool

node_id(self: omni.graph.core._omni_graph_core.Node) → int

Returns a unique identifier value for this node.

Returns: Unique identifier value for the node - not persistent through file save and load
Return type: int

register_on_connected_callback(self: omni.graph.core._omni_graph_core.Node, callback: object) → int

Registers a callback to be invoked when the node has attributes connected. The callback takes 2 parameters: the attributes from and attribute to of the connection.

Parameters: callback (callable) – The callback function
Returns: A handle that could be used for deregistration.
Return type: int

register_on_disconnected_callback(self: omni.graph.core._omni_graph_core.Node, callback: object) → int

Registers a callback to be invoked when the node has attributes disconnected. The callback takes 2 parameters: the attributes from and attribute to of the disconnection.

Parameters: callback (callable) – The callback function
Returns: A handle identifying the callback that can be used for deregistration.

register_on_path_changed_callback(self: omni.graph.core._omni_graph_core.Node, callback: object) → int

Registers a callback to be invoked when a path changes in the stage. The callback takes 1 parameter: a list of the paths that were changed. [DEPRECATED]

Parameters: callback (callable) – The callback function
Returns: A handle identifying the callback that can be used for deregistration.

remove_attribute(self: omni.graph.core._omni_graph_core.Node, attributeName: str) → bool

Removes an attribute with the specified name and type and returns success state.

Parameters: attributeName (str) – Name of the attribute.
Returns: True if the removal was successful, False if the attribute was not found
Return type: bool

request_compute(self: omni.graph.core._omni_graph_core.Node) → bool

Requests a compute of this node

Returns: True if the request was successful, False if there was an error
Return type: bool

resolve_coupled_attributes(self: omni.graph.core._omni_graph_core.Node, attributesArray: List[omni.graph.core._omni_graph_core.Attribute]) → bool

Resolves attribute types given a set of attributes which are fully type coupled. For example if node ‘Increment’ has one input attribute ‘a’ and one output attribute ‘b’ and the types of ‘a’ and ‘b’ should always match. If the input is resolved then this function will resolve the output to the same type. It will also take into consideration available conversions on the input size. The type of the first (resolved) provided attribute will be used to resolve others or select appropriate conversions

Note that input attribute types are never inferred from output attribute types.

This function should only be called from the INodeType function ‘on_connection_type_resolve’

Parameters: attributesArray (list[omni.graph.core.Attribute]) – Array of attributes to be resolved as a coupled group
Returns: True if successful, False otherwise, usually due to mismatched or missing resolved types
Return type: bool

resolve_partially_coupled_attributes(self: omni.graph.core._omni_graph_core.Node, attributesArray: List[omni.graph.core._omni_graph_core.Attribute], tuplesArray: list, arraySizesArray: list, rolesArray: List[omni::fabric::AttributeRole]) → bool

Resolves attribute types given a set of attributes, that can have differing tuple counts and/or array depth, and differing but convertible base data type. The three input buffers are tied together, holding the attribute, the tuple count, and the array depth of the types to be coupled. This function will solve base type conversion by targeting the first provided type in the list, for all other ones that require it.

For example if node ‘makeTuple2’ has two input attributes ‘a’ and ‘b’ and one output ‘c’ and we want to resolve any float connection to the types ‘a’:float, ‘b’:float, ‘c’:float[2] (convertible base types and different tuple counts) then the input buffers would contain: attrsBuf = [a, b, c] tuplesBuf = [1, 1, 2] arrayDepthsBuf = [0, 0, 0] rolesBuf = [AttributeRole::eNone, AttributeRole::eNone, AttributeRole::eNone]

This is worth noting that ‘b’ could be of any type convertible to float. But since the first provided attribute is ‘a’, the type of ‘a’ will be used to propagate the type resolution.

Note that input attribute types are never inferred from output attribute types.

This function should only be called from the INodeType function ‘on_connection_type_resolve’

Parameters

attributesArray (list[omni.graph.core.Attribute]) – Array of attributes to be resolved as a coupled group
tuplesArray (list[int]) – Array of tuple count desired for each corresponding attribute. Any value of None indicates the found tuple count is to be used when resolving.
arraySizesArray (list[int]) – Array of array depth desired for each corresponding attribute. Any value of None indicates the found array depth is to be used when resolving.
rolesArray (list[omni.graph.core.AttributeRole]) – Array of role desired for each corresponding attribute. A value of AttributeRole::eUnknown indicates the found role is to be used when resolving.

Returns

True if successful, False otherwise, usually due to mismatched or missing resolved types

Return type

bool

set_compute_incomplete(self: omni.graph.core._omni_graph_core.Node) → None: Informs the system that compute is incomplete for this frame. In lazy evaluation systems, this node will be scheduled on the next frame since it still has more work to do.

set_disabled(self: omni.graph.core._omni_graph_core.Node, disabled: bool) → None

Sets whether the node is disabled or not.

Parameters: disabled (bool) – True for disabled, False for not.