Functions
HAPI_DECL	HAPI_GetParameters (const HAPI_Session session, HAPI_NodeId node_id, HAPI_ParmInfo parm_infos_array, int start, int length)
	Fill an array of HAPI_ParmInfo structs with parameter information from the asset instance node. More...

HAPI_DECL	HAPI_GetParmInfo (const HAPI_Session session, HAPI_NodeId node_id, HAPI_ParmId parm_id, HAPI_ParmInfo parm_info)
	Get the parm info of a parameter by parm id. More...

HAPI_DECL	HAPI_GetParmIdFromName (const HAPI_Session session, HAPI_NodeId node_id, const char parm_name, HAPI_ParmId *parm_id)
	All parameter APIs require a HAPI_ParmId but if you know the parameter you wish to operate on by name than you can use this function to get its HAPI_ParmId. If the parameter with the given name is not found the parameter id returned will be -1. More...

HAPI_DECL	HAPI_GetParmInfoFromName (const HAPI_Session session, HAPI_NodeId node_id, const char parm_name, HAPI_ParmInfo *parm_info)
	Get the parm info of a parameter by name. More...

HAPI_DECL	HAPI_GetParmTagName (const HAPI_Session session, HAPI_NodeId node_id, HAPI_ParmId parm_id, int tag_index, HAPI_StringHandle tag_name)
	Get the tag name on a parameter given an index. More...

HAPI_DECL	HAPI_GetParmTagValue (const HAPI_Session session, HAPI_NodeId node_id, HAPI_ParmId parm_id, const char tag_name, HAPI_StringHandle *tag_value)
	Get the tag value on a parameter given the tag name. More...

HAPI_DECL	HAPI_ParmHasTag (const HAPI_Session session, HAPI_NodeId node_id, HAPI_ParmId parm_id, const char tag_name, HAPI_Bool *has_tag)
	See if a parameter has a specific tag. More...

HAPI_DECL	HAPI_ParmHasExpression (const HAPI_Session session, HAPI_NodeId node_id, const char parm_name, int index, HAPI_Bool *has_expression)
	See if a parameter has an expression. More...

HAPI_DECL	HAPI_GetParmWithTag (const HAPI_Session session, HAPI_NodeId node_id, const char tag_name, HAPI_ParmId *parm_id)
	Get the first parm with a specific, ideally unique, tag on it. This is particularly useful for getting the ogl parameters on a material node. More...

HAPI_DECL	HAPI_GetParmExpression (const HAPI_Session session, HAPI_NodeId node_id, const char parm_name, int index, HAPI_StringHandle *value)
	Get single integer or float parm expression by name or Null string if no expression is present. More...

HAPI_DECL	HAPI_RevertParmToDefault (const HAPI_Session session, HAPI_NodeId node_id, const char parm_name, int index)
	Revert single parm by name to default. More...

HAPI_DECL	HAPI_RevertParmToDefaults (const HAPI_Session session, HAPI_NodeId node_id, const char parm_name)
	Revert all instances of the parm by name to defaults. More...

HAPI_DECL	HAPI_SetParmExpression (const HAPI_Session session, HAPI_NodeId node_id, const char value, HAPI_ParmId parm_id, int index)
	Set (push) an expression string. We can only set a single value at a time because we want to avoid fixed size string buffers. More...

HAPI_DECL	HAPI_RemoveParmExpression (const HAPI_Session *session, HAPI_NodeId node_id, HAPI_ParmId parm_id, int index)
	Remove the expression string, leaving the value of the parm at the current value of the expression. More...

HAPI_DECL	HAPI_GetParmIntValue (const HAPI_Session session, HAPI_NodeId node_id, const char parm_name, int index, int *value)
	Get single parm int value by name. More...

HAPI_DECL	HAPI_GetParmIntValues (const HAPI_Session session, HAPI_NodeId node_id, int values_array, int start, int length)
	Fill an array of parameter int values. This is more efficient than calling HAPI_GetParmIntValue() individually for each parameter value. More...

HAPI_DECL	HAPI_GetParmFloatValue (const HAPI_Session session, HAPI_NodeId node_id, const char parm_name, int index, float *value)
	Get single parm float value by name. More...

HAPI_DECL	HAPI_GetParmFloatValues (const HAPI_Session session, HAPI_NodeId node_id, float values_array, int start, int length)
	Fill an array of parameter float values. This is more efficient than calling HAPI_GetParmFloatValue() individually for each parameter value. More...

HAPI_DECL	HAPI_GetParmStringValue (const HAPI_Session session, HAPI_NodeId node_id, const char parm_name, int index, HAPI_Bool evaluate, HAPI_StringHandle *value)
	Get single parm string value by name. More...

HAPI_DECL	HAPI_GetParmStringValues (const HAPI_Session session, HAPI_NodeId node_id, HAPI_Bool evaluate, HAPI_StringHandle values_array, int start, int length)
	Fill an array of parameter string handles. These handles must be used in conjunction with HAPI_GetString() to get the actual string values. This is more efficient than calling HAPI_GetParmStringValue() individually for each parameter value. More...

HAPI_DECL	HAPI_GetParmNodeValue (const HAPI_Session session, HAPI_NodeId node_id, const char parm_name, HAPI_NodeId *value)
	Get a single node id parm value of an Op Path parameter. This is how you see which node is connected as an input for the current node (via parameter). More...

HAPI_DECL	HAPI_GetParmFile (const HAPI_Session session, HAPI_NodeId node_id, const char parm_name, const char destination_directory, const char destination_file_name)
	Extract a file specified by path on a parameter. This will copy the file to the destination directory from wherever it might be, inlcuding inside the asset definition or online. More...

HAPI_DECL	HAPI_GetParmChoiceLists (const HAPI_Session session, HAPI_NodeId node_id, HAPI_ParmChoiceInfo parm_choices_array, int start, int length)
	Fill an array of HAPI_ParmChoiceInfo structs with parameter choice list information from the asset instance node. More...

HAPI_DECL	HAPI_SetParmIntValue (const HAPI_Session session, HAPI_NodeId node_id, const char parm_name, int index, int value)
	Set single parm int value by name. More...

HAPI_DECL	HAPI_SetParmIntValues (const HAPI_Session session, HAPI_NodeId node_id, const int values_array, int start, int length)
	Set (push) an array of parameter int values. More...

HAPI_DECL	HAPI_SetParmFloatValue (const HAPI_Session session, HAPI_NodeId node_id, const char parm_name, int index, float value)
	Set single parm float value by name. More...

HAPI_DECL	HAPI_SetParmFloatValues (const HAPI_Session session, HAPI_NodeId node_id, const float values_array, int start, int length)
	Set (push) an array of parameter float values. More...

HAPI_DECL	HAPI_SetParmStringValue (const HAPI_Session session, HAPI_NodeId node_id, const char value, HAPI_ParmId parm_id, int index)
	Set (push) a string value. We can only set a single value at a time because we want to avoid fixed size string buffers. More...

HAPI_DECL	HAPI_SetParmNodeValue (const HAPI_Session session, HAPI_NodeId node_id, const char parm_name, HAPI_NodeId value)
	Set a node id parm value of an Op Path parameter. For example, This is how you connect the geometry output of an asset to the geometry input of another asset - whether the input is a parameter or a node input (the top of the node). Node inputs get converted top parameters in HAPI. More...

HAPI_DECL	HAPI_InsertMultiparmInstance (const HAPI_Session *session, HAPI_NodeId node_id, HAPI_ParmId parm_id, int instance_position)
	Insert an instance of a multiparm before instance_position. More...

HAPI_DECL	HAPI_RemoveMultiparmInstance (const HAPI_Session *session, HAPI_NodeId node_id, HAPI_ParmId parm_id, int instance_position)
	Remove the instance of a multiparm given by instance_position. More...

HAPI_DECL	HAPI_GetHandleInfo (const HAPI_Session session, HAPI_NodeId node_id, HAPI_HandleInfo handle_infos_array, int start, int length)
	Fill an array of HAPI_HandleInfo structs with information about every exposed user manipulation handle on the node. More...

HAPI_DECL	HAPI_GetHandleBindingInfo (const HAPI_Session session, HAPI_NodeId node_id, int handle_index, HAPI_HandleBindingInfo handle_binding_infos_array, int start, int length)
	Fill an array of HAPI_HandleBindingInfo structs with information about the binding of a particular handle on the given node. More...

Detailed Description

Functions for wroking with Node parameters (parms)

Function Documentation

HAPI_DECL HAPI_GetHandleBindingInfo	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		int	handle_index,
		HAPI_HandleBindingInfo *	handle_binding_infos_array,
		int	start,
		int	length
	)

Fill an array of HAPI_HandleBindingInfo structs with information about the binding of a particular handle on the given node.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[in]	handle_index	The index of the handle, from 0 to handleCount - 1 from the call to HAPI_GetAssetInfo().
[out]	handle_binding_infos_array	Array of HAPI_HandleBindingInfo at least the size of length.
[in]	start	First index of range. Must be at least 0 and at most HAPI_HandleInfo::bindingsCount - 1.
[in]	length	Must be at least 1 and at most HAPI_HandleInfo::bindingsCount - start.

HAPI_DECL HAPI_GetHandleInfo	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		HAPI_HandleInfo *	handle_infos_array,
		int	start,
		int	length
	)

Fill an array of HAPI_HandleInfo structs with information about every exposed user manipulation handle on the node.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[out]	handle_infos_array	Array of HAPI_HandleInfo at least the size of length.
[in]	start	First index of range. Must be at least 0 and at most HAPI_AssetInfo::handleCount - 1.
[in]	length	Must be at least 1 and at most HAPI_AssetInfo::handleCount - start.

HAPI_DECL HAPI_GetParameters	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		HAPI_ParmInfo *	parm_infos_array,
		int	start,
		int	length
	)

Fill an array of HAPI_ParmInfo structs with parameter information from the asset instance node.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[out]	parm_infos_array	Array of HAPI_ParmInfo at least the size of length.
[in]	start	First index of range. Must be at least 0 and at most HAPI_NodeInfo::parmCount - 1.
[in]	length	Must be at least 1 and at most HAPI_NodeInfo::parmCount - start.

HAPI_DECL HAPI_GetParmChoiceLists	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		HAPI_ParmChoiceInfo *	parm_choices_array,
		int	start,
		int	length
	)

Fill an array of HAPI_ParmChoiceInfo structs with parameter choice list information from the asset instance node.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[out]	parm_choices_array	Array of HAPI_ParmChoiceInfo exactly the size of length.
[in]	start	First index of range. Must be at least 0 and at most HAPI_NodeInfo::parmChoiceCount - 1.
[in]	length	Must be at least 1 and at most HAPI_NodeInfo::parmChoiceCount - start.

HAPI_DECL HAPI_GetParmExpression	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		const char *	parm_name,
		int	index,
		HAPI_StringHandle *	value
	)

Get single integer or float parm expression by name or Null string if no expression is present.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[in]	parm_name	The parm name.
[in]	index	Index within the parameter's values tuple.
[out]	value	The returned string value.

HAPI_DECL HAPI_GetParmFile	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		const char *	parm_name,
		const char *	destination_directory,
		const char *	destination_file_name
	)

Extract a file specified by path on a parameter. This will copy the file to the destination directory from wherever it might be, inlcuding inside the asset definition or online.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[in]	parm_name	The name of the parameter.
[in]	destination_directory	The destination directory to copy the file to.
[in]	destination_file_name	The destination file name.

HAPI_DECL HAPI_GetParmFloatValue	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		const char *	parm_name,
		int	index,
		float *	value
	)

Get single parm float value by name.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[in]	parm_name	The parm name.
[in]	index	Index within the parameter's values tuple.
[out]	value	The returned float value.

HAPI_DECL HAPI_GetParmFloatValues	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		float *	values_array,
		int	start,
		int	length
	)

Fill an array of parameter float values. This is more efficient than calling HAPI_GetParmFloatValue() individually for each parameter value.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[out]	values_array	Array of floats at least the size of length.
[in]	start	First index of range. Must be at least 0 and at most HAPI_NodeInfo::parmFloatValueCount - 1.
[in]	length	Must be at least 1 and at most HAPI_NodeInfo::parmFloatValueCount - start.

HAPI_DECL HAPI_GetParmIdFromName	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		const char *	parm_name,
		HAPI_ParmId *	parm_id
	)

All parameter APIs require a HAPI_ParmId but if you know the parameter you wish to operate on by name than you can use this function to get its HAPI_ParmId. If the parameter with the given name is not found the parameter id returned will be -1.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[in]	parm_name	The parm name.
[out]	parm_id	The return value. The parameter's HAPI_ParmId. If the parameter with the given name is not found the parameter id returned will be -1.

HAPI_DECL HAPI_GetParmInfo	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		HAPI_ParmId	parm_id,
		HAPI_ParmInfo *	parm_info
	)

Get the parm info of a parameter by parm id.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[in]	parm_id	The parm id.
[out]	parm_info	The returned parm info.

HAPI_DECL HAPI_GetParmInfoFromName	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		const char *	parm_name,
		HAPI_ParmInfo *	parm_info
	)

Get the parm info of a parameter by name.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[in]	parm_name	The parm name.
[out]	parm_info	The returned parm info.

HAPI_DECL HAPI_GetParmIntValue	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		const char *	parm_name,
		int	index,
		int *	value
	)

Get single parm int value by name.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[in]	parm_name	The parm name.
[in]	index	Index within the parameter's values tuple.
[out]	value	The returned int value.

HAPI_DECL HAPI_GetParmIntValues	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		int *	values_array,
		int	start,
		int	length
	)

Fill an array of parameter int values. This is more efficient than calling HAPI_GetParmIntValue() individually for each parameter value.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[out]	values_array	Array of ints at least the size of length.
[in]	start	First index of range. Must be at least 0 and at most HAPI_NodeInfo::parmIntValueCount - 1.
[in]	length	Must be at least 1 and at most HAPI_NodeInfo::parmIntValueCount - start.

HAPI_DECL HAPI_GetParmNodeValue	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		const char *	parm_name,
		HAPI_NodeId *	value
	)

Get a single node id parm value of an Op Path parameter. This is how you see which node is connected as an input for the current node (via parameter).

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[in]	parm_name	The name of the parameter.
[out]	value	The node id of the node being pointed to by the parm. If there is no node found, -1 will be returned.

HAPI_DECL HAPI_GetParmStringValue	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		const char *	parm_name,
		int	index,
		HAPI_Bool	evaluate,
		HAPI_StringHandle *	value
	)

Get single parm string value by name.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[in]	parm_name	The name of the parameter.
[in]	index	Index within the parameter's values tuple.
[in]	evaluate	Whether or not to evaluate the string expression. For example, the string "$F" would evaluate to the current frame number. So, passing in evaluate = false would give you back the string "$F" and passing in evaluate = true would give you back "1" (assuming the current frame is 1).
[out]	value	The returned string value.

HAPI_DECL HAPI_GetParmStringValues	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		HAPI_Bool	evaluate,
		HAPI_StringHandle *	values_array,
		int	start,
		int	length
	)

Fill an array of parameter string handles. These handles must be used in conjunction with HAPI_GetString() to get the actual string values. This is more efficient than calling HAPI_GetParmStringValue() individually for each parameter value.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[in]	evaluate	Whether or not to evaluate the string expression. For example, the string "$F" would evaluate to the current frame number. So, passing in evaluate = false would give you back the string "$F" and passing in evaluate = true would give you back "1" (assuming the current frame is 1).
[out]	values_array	Array of integers at least the size of length.
[in]	start	First index of range. Must be at least 0 and at most HAPI_NodeInfo::parmStringValueCount - 1.
[in]	length	Must be at least 1 and at most HAPI_NodeInfo::parmStringValueCount - start.

HAPI_DECL HAPI_GetParmTagName	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		HAPI_ParmId	parm_id,
		int	tag_index,
		HAPI_StringHandle *	tag_name
	)

Get the tag name on a parameter given an index.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[in]	parm_id	The parm id.
[in]	tag_index	The tag index, which should be between 0 and HAPI_ParmInfo::tagCount - 1.

Note: These indices are invalidated whenever tags are added to parameters. Do not store these or expect them to be the same if the scene is modified.

Parameters

[out] tag_name The returned tag name. This string handle will be valid until another call to HAPI_GetParmTagName().

HAPI_DECL HAPI_GetParmTagValue	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		HAPI_ParmId	parm_id,
		const char *	tag_name,
		HAPI_StringHandle *	tag_value
	)

Get the tag value on a parameter given the tag name.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[in]	parm_id	The parm id.
[in]	tag_name	The tag name, either known or returned by HAPI_GetParmTagName().
[out]	tag_value	The returned tag value. This string handle will be valid until another call to HAPI_GetParmTagValue().

HAPI_DECL HAPI_GetParmWithTag	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		const char *	tag_name,
		HAPI_ParmId *	parm_id
	)

Get the first parm with a specific, ideally unique, tag on it. This is particularly useful for getting the ogl parameters on a material node.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[in]	tag_name	The tag name to look for.
[out]	parm_id	The returned parm id. This will be -1 if no parm was found with this tag.

HAPI_DECL HAPI_InsertMultiparmInstance	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		HAPI_ParmId	parm_id,
		int	instance_position
	)

Insert an instance of a multiparm before instance_position.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[in]	parm_id	A parm id given by a HAPI_ParmInfo struct that has type HAPI_PARMTYPE_MULTIPARMLIST.
[in]	instance_position	The new instance will be inserted at this position index. Do note the multiparms can start at position 1 or 0. Use HAPI_ParmInfo::instanceStartOffset to distinguish.

HAPI_DECL HAPI_ParmHasExpression	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		const char *	parm_name,
		int	index,
		HAPI_Bool *	has_expression
	)

See if a parameter has an expression.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[in]	parm_name	The parm name.
[in]	index	The parm index.
[out]	has_expression	True if an expression exists on the parameter, false otherwise.

HAPI_DECL HAPI_ParmHasTag	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		HAPI_ParmId	parm_id,
		const char *	tag_name,
		HAPI_Bool *	has_tag
	)

See if a parameter has a specific tag.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[in]	parm_id	The parm id.
[in]	tag_name	The tag name to look for.
[out]	has_tag	True if the tag exists on the parameter, false otherwise.

HAPI_DECL HAPI_RemoveMultiparmInstance	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		HAPI_ParmId	parm_id,
		int	instance_position
	)

Remove the instance of a multiparm given by instance_position.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[in]	parm_id	A parm id given by a HAPI_ParmInfo struct that has type HAPI_PARMTYPE_MULTIPARMLIST.
[in]	instance_position	The instance at instance_position will removed.

HAPI_DECL HAPI_RemoveParmExpression	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		HAPI_ParmId	parm_id,
		int	index
	)

Remove the expression string, leaving the value of the parm at the current value of the expression.

Note: Regardless of the value, when calling this function on a parameter, if that parameter has a callback function attached to it, that callback function will be called. For example, if the parameter is a button the button will be pressed.; In threaded mode, this is an async call!

This API will invoke the cooking thread if threading is enabled. This means it will return immediately. Use the status and cooking count APIs under DIAGNOSTICS to get a sense of the progress. All other API calls will block until the cook operation has finished.

Also note that the cook result won't be of type HAPI_STATUS_CALL_RESULT like all calls (including this one). Whenever the threading cook is done it will fill the cook result which is queried using HAPI_STATUS_COOK_RESULT.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[in]	parm_id	Parameter id of the parameter being updated.
[in]	index	Index within the parameter's values tuple.

HAPI_DECL HAPI_RevertParmToDefault	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		const char *	parm_name,
		int	index
	)

Revert single parm by name to default.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[in]	parm_name	The parm name.
[in]	index	Index within the parameter's values tuple.

HAPI_DECL HAPI_RevertParmToDefaults	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		const char *	parm_name
	)

Revert all instances of the parm by name to defaults.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[in]	parm_name	The parm name.

HAPI_DECL HAPI_SetParmExpression	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		const char *	value,
		HAPI_ParmId	parm_id,
		int	index
	)

Set (push) an expression string. We can only set a single value at a time because we want to avoid fixed size string buffers.

Note: Regardless of the value, when calling this function on a parameter, if that parameter has a callback function attached to it, that callback function will be called. For example, if the parameter is a button the button will be pressed.; In threaded mode, this is an async call!

This API will invoke the cooking thread if threading is enabled. This means it will return immediately. Use the status and cooking count APIs under DIAGNOSTICS to get a sense of the progress. All other API calls will block until the cook operation has finished.

Also note that the cook result won't be of type HAPI_STATUS_CALL_RESULT like all calls (including this one). Whenever the threading cook is done it will fill the cook result which is queried using HAPI_STATUS_COOK_RESULT.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[in]	value	The expression string.
[in]	parm_id	Parameter id of the parameter being updated.
[in]	index	Index within the parameter's values tuple.

HAPI_DECL HAPI_SetParmFloatValue	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		const char *	parm_name,
		int	index,
		float	value
	)

Set single parm float value by name.

Note: Regardless of the value, when calling this function on a parameter, if that parameter has a callback function attached to it, that callback function will be called. For example, if the parameter is a button the button will be pressed.; In threaded mode, this is an async call!

This API will invoke the cooking thread if threading is enabled. This means it will return immediately. Use the status and cooking count APIs under DIAGNOSTICS to get a sense of the progress. All other API calls will block until the cook operation has finished.

Also note that the cook result won't be of type HAPI_STATUS_CALL_RESULT like all calls (including this one). Whenever the threading cook is done it will fill the cook result which is queried using HAPI_STATUS_COOK_RESULT.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[in]	parm_name	The parm name.
[in]	index	Index within the parameter's values tuple.
[in]	value	The float value.

HAPI_DECL HAPI_SetParmFloatValues	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		const float *	values_array,
		int	start,
		int	length
	)

Set (push) an array of parameter float values.

Note: Regardless of the values, when calling this function on a set of parameters, if any parameter has a callback function attached to it, that callback function will be called. For example, if the parameter is a button the button will be pressed.; In threaded mode, this is an async call!

This API will invoke the cooking thread if threading is enabled. This means it will return immediately. Use the status and cooking count APIs under DIAGNOSTICS to get a sense of the progress. All other API calls will block until the cook operation has finished.

Also note that the cook result won't be of type HAPI_STATUS_CALL_RESULT like all calls (including this one). Whenever the threading cook is done it will fill the cook result which is queried using HAPI_STATUS_COOK_RESULT.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[in]	values_array	Array of floats at least the size of length.
[in]	start	First index of range. Must be at least 0 and at most HAPI_NodeInfo::parmFloatValueCount - 1.
[in]	length	Must be at least 1 and at most HAPI_NodeInfo::parmFloatValueCount - start.

HAPI_DECL HAPI_SetParmIntValue	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		const char *	parm_name,
		int	index,
		int	value
	)

Set single parm int value by name.

Note: Regardless of the value, when calling this function on a parameter, if that parameter has a callback function attached to it, that callback function will be called. For example, if the parameter is a button the button will be pressed.; In threaded mode, this is an async call!

This API will invoke the cooking thread if threading is enabled. This means it will return immediately. Use the status and cooking count APIs under DIAGNOSTICS to get a sense of the progress. All other API calls will block until the cook operation has finished.

Also note that the cook result won't be of type HAPI_STATUS_CALL_RESULT like all calls (including this one). Whenever the threading cook is done it will fill the cook result which is queried using HAPI_STATUS_COOK_RESULT.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[in]	parm_name	The parm name.
[in]	index	Index within the parameter's values tuple.
[in]	value	The int value.

HAPI_DECL HAPI_SetParmIntValues	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		const int *	values_array,
		int	start,
		int	length
	)

Set (push) an array of parameter int values.

Note: Regardless of the values, when calling this function on a set of parameters, if any parameter has a callback function attached to it, that callback function will be called. For example, if the parameter is a button the button will be pressed.; In threaded mode, this is an async call!

This API will invoke the cooking thread if threading is enabled. This means it will return immediately. Use the status and cooking count APIs under DIAGNOSTICS to get a sense of the progress. All other API calls will block until the cook operation has finished.

Also note that the cook result won't be of type HAPI_STATUS_CALL_RESULT like all calls (including this one). Whenever the threading cook is done it will fill the cook result which is queried using HAPI_STATUS_COOK_RESULT.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[in]	values_array	Array of integers at least the size of length.
[in]	start	First index of range. Must be at least 0 and at most HAPI_NodeInfo::parmIntValueCount - 1.
[in]	length	Must be at least 1 and at most HAPI_NodeInfo::parmIntValueCount - start.

HAPI_DECL HAPI_SetParmNodeValue	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		const char *	parm_name,
		HAPI_NodeId	value
	)

Set a node id parm value of an Op Path parameter. For example, This is how you connect the geometry output of an asset to the geometry input of another asset - whether the input is a parameter or a node input (the top of the node). Node inputs get converted top parameters in HAPI.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[in]	parm_name	The name of the parameter.
[in]	value	The node id of the node being connected. Pass -1 to disconnect.

HAPI_DECL HAPI_SetParmStringValue	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		const char *	value,
		HAPI_ParmId	parm_id,
		int	index
	)

Set (push) a string value. We can only set a single value at a time because we want to avoid fixed size string buffers.

Note: Regardless of the value, when calling this function on a parameter, if that parameter has a callback function attached to it, that callback function will be called. For example, if the parameter is a button the button will be pressed.; In threaded mode, this is an async call!

This API will invoke the cooking thread if threading is enabled. This means it will return immediately. Use the status and cooking count APIs under DIAGNOSTICS to get a sense of the progress. All other API calls will block until the cook operation has finished.

Also note that the cook result won't be of type HAPI_STATUS_CALL_RESULT like all calls (including this one). Whenever the threading cook is done it will fill the cook result which is queried using HAPI_STATUS_COOK_RESULT.

Parameters

[in]	session	The session of Houdini you are interacting with. See Sessions for more on sessions. Pass NULL to just use the default in-process session.
[in]	node_id	The node id.
[in]	value	The string value.
[in]	parm_id	Parameter id of the parameter being updated.
[in]	index	Index within the parameter's values tuple.