Assets

Functions
HAPI_DECL	HAPI_LoadAssetLibraryFromFile (const HAPI_Session *session, const char *file_path, HAPI_Bool allow_overwrite, HAPI_AssetLibraryId *library_id)
	Loads a Houdini asset library (OTL) from a .otl file. It does NOT create anything inside the Houdini scene. More...
HAPI_DECL	HAPI_LoadAssetLibraryFromMemory (const HAPI_Session *session, const char *library_buffer, int library_buffer_length, HAPI_Bool allow_overwrite, HAPI_AssetLibraryId *library_id)
	Loads a Houdini asset library (OTL) from memory. It does NOT create anything inside the Houdini scene. More...
HAPI_DECL	HAPI_GetAvailableAssetCount (const HAPI_Session *session, HAPI_AssetLibraryId library_id, int *asset_count)
	Get the number of assets contained in an asset library. You should call HAPI_LoadAssetLibraryFromFile() prior to get a library_id. More...
HAPI_DECL	HAPI_GetAvailableAssets (const HAPI_Session *session, HAPI_AssetLibraryId library_id, HAPI_StringHandle *asset_names_array, int asset_count)
	Get the names of the assets contained in an asset library. More...
HAPI_DECL	HAPI_GetAssetInfo (const HAPI_Session *session, HAPI_NodeId node_id, HAPI_AssetInfo *asset_info)
	Fill an asset_info struct from a node. More...
HAPI_DECL	HAPI_GetAssetDefinitionParmCounts (const HAPI_Session *session, HAPI_AssetLibraryId library_id, const char *asset_name, int *parm_count, int *int_value_count, int *float_value_count, int *string_value_count, int *choice_value_count)
	Get the number of asset parameters contained in an asset library, as well as the number of parameter int, float, string, and choice values. More...
HAPI_DECL	HAPI_GetAssetDefinitionParmInfos (const HAPI_Session *session, HAPI_AssetLibraryId library_id, const char *asset_name, HAPI_ParmInfo *parm_infos_array, int start, int length)
	Fill an array of HAPI_ParmInfo structs with parameter information for the specified asset in the specified asset library. More...
HAPI_DECL	HAPI_GetAssetDefinitionParmValues (const HAPI_Session *session, HAPI_AssetLibraryId library_id, const char *asset_name, int *int_values_array, int int_start, int int_length, float *float_values_array, int float_start, int float_length, HAPI_Bool string_evaluate, HAPI_StringHandle *string_values_array, int string_start, int string_length, HAPI_ParmChoiceInfo *choice_values_array, int choice_start, int choice_length)
	Fill arrays of parameter int values, float values, string values, and choice values for parameters in the specified asset in the specified asset library. More...
HAPI_DECL	HAPI_GetAssetDefinitionParmTagName (const HAPI_Session *session, HAPI_AssetLibraryId library_id, const char *asset_name, HAPI_ParmId parm_id, int tag_index, HAPI_StringHandle *tag_name)
HAPI_DECL	HAPI_GetAssetDefinitionParmTagValue (const HAPI_Session *session, HAPI_AssetLibraryId library_id, const char *asset_name, HAPI_ParmId parm_id, const char *tag_name, HAPI_StringHandle *tag_value)
HAPI_DECL	HAPI_GetLoadedAssetLibraryCount (const HAPI_Session *session, int *count)
	Gets the number of HDAs that have been loaded by Houdini. More...
HAPI_DECL	HAPI_GetAssetLibraryIds (const HAPI_Session *session, HAPI_AssetLibraryId *asset_library_ids_array, int start, int length)
	Gets the HAPI_AssetLibraryId's for HDAs that are loaded in Houdini. More...
HAPI_DECL	HAPI_GetAssetLibraryFilePath (const HAPI_Session *session, HAPI_AssetLibraryId asset_library_id, HAPI_StringHandle *file_path_sh)
	Gets the HAPI_StringHandle for the file path of a loaded asset library. More...

Detailed Description

Functions for managing asset libraries

Function Documentation

HAPI_DECL HAPI_GetAssetDefinitionParmCounts	(	const HAPI_Session *	session,
		HAPI_AssetLibraryId	library_id,
		const char *	asset_name,
		int *	parm_count,
		int *	int_value_count,
		int *	float_value_count,
		int *	string_value_count,
		int *	choice_value_count
	)

Get the number of asset parameters contained in an asset library, as well as the number of parameter int, float, string, and choice values.

This does not create the asset in the session. Use this for faster querying of asset parameters compared to creating the asset node and querying the node's parameters.

This does require HAPI_LoadAssetLibraryFromFile() to be called prior, in order to load the asset library and acquire library_id. Then HAPI_GetAvailableAssetCount and HAPI_GetAvailableAssets should be called to get the asset_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]	library_id	Returned by HAPI_LoadAssetLibraryFromFile().
[in]	asset_name	Name of the asset to get the parm counts for.
[out]	parm_count	The number of parameters in the asset library.
[out]	int_value_count	The number of int values for parameters in the asset library.
[out]	float_value_count	The number of float values for parameters in the asset library.
[out]	string_value_count	The number of string values for parameters in the asset library.
[out]	choice_value_count	The number of choice values for parameters in the asset library.

HAPI_DECL HAPI_GetAssetDefinitionParmInfos	(	const HAPI_Session *	session,
		HAPI_AssetLibraryId	library_id,
		const char *	asset_name,
		HAPI_ParmInfo *	parm_infos_array,
		int	start,
		int	length
	)

Fill an array of HAPI_ParmInfo structs with parameter information for the specified asset in the specified asset library.

This does not create the asset in the session. Use this for faster querying of asset parameters compared to creating the asset node and querying the node's parameters.

This does require HAPI_LoadAssetLibraryFromFile() to be called prior, in order to load the asset library and acquire library_id. HAPI_GetAssetDefinitionParmCounts should be called prior to acquire the count for the size of parm_infos_array.

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]	library_id	Returned by HAPI_LoadAssetLibraryFromFile().
[in]	asset_name	Name of the asset to get the parm counts for.
[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 parm_count - 1 acquired from HAPI_GetAssetInfo.
[in]	length	Must be at least 1 and at most parm_count - start acquired from HAPI_GetAssetInfo

HAPI_DECL HAPI_GetAssetDefinitionParmTagName	(	const HAPI_Session *	session,
		HAPI_AssetLibraryId	library_id,
		const char *	asset_name,
		HAPI_ParmId	parm_id,
		int	tag_index,
		HAPI_StringHandle *	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]	library_id	Returned by HAPI_LoadAssetLibraryFromFile().
[in]	asset_name	Name of the asset that the parm tag is being retrieved from.
[in]	parm_id	Id of the parm that the tag belongs to.
[in]	tag_index	The index of the parm tag to retrieve the name of.
[out]	tag_name	The string handle for the specified parm tag's name.

HAPI_DECL HAPI_GetAssetDefinitionParmTagValue	(	const HAPI_Session *	session,
		HAPI_AssetLibraryId	library_id,
		const char *	asset_name,
		HAPI_ParmId	parm_id,
		const char *	tag_name,
		HAPI_StringHandle *	tag_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]	library_id	Returned by HAPI_LoadAssetLibraryFromFile().
[in]	asset_name	Name of the asset that the parm tag is being retrieved from.
[in]	parm_id	Id of the parm that the tag belongs to.
[in]	tag_name	The name of the parm tag to retrieve the value of.
[out]	tag_value	The string handle for the specified parm tag's value.

HAPI_DECL HAPI_GetAssetDefinitionParmValues	(	const HAPI_Session *	session,
		HAPI_AssetLibraryId	library_id,
		const char *	asset_name,
		int *	int_values_array,
		int	int_start,
		int	int_length,
		float *	float_values_array,
		int	float_start,
		int	float_length,
		HAPI_Bool	string_evaluate,
		HAPI_StringHandle *	string_values_array,
		int	string_start,
		int	string_length,
		HAPI_ParmChoiceInfo *	choice_values_array,
		int	choice_start,
		int	choice_length
	)

Fill arrays of parameter int values, float values, string values, and choice values for parameters in the specified asset in the specified asset library.

This does not create the asset in the session. Use this for faster querying of asset parameters compared to creating the asset node and querying the node's parameters. Note that only default values are retrieved.

This does require HAPI_LoadAssetLibraryFromFile() to be called prior, in order to load the asset library and acquire library_id. HAPI_GetAssetDefinitionParmCounts should be called prior to acquire the counts for the sizes of the values arrays.

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]	library_id	Returned by HAPI_LoadAssetLibraryFromFile().
[in]	asset_name	Name of the asset to get the parm counts for.
[out]	int_values_array	Array of ints at least the size of int_length.
[in]	int_start	First index of range for int_values_array. Must be at least 0 and at most int_value_count - 1 acquired from HAPI_GetAssetDefinitionParmCounts.
[in]	int_length	Must be at least 0 and at most int_value_count - int_start acquired from HAPI_GetAssetDefinitionParmCounts.
[out]	float_values_array	Array of floats at least the size of float_length.
[in]	float_start	First index of range for float_values_array. Must be at least 0 and at most float_value_count - 1 acquired from HAPI_GetAssetDefinitionParmCounts.
[in]	float_length	Must be at least 0 and at most float_value_count - float_start acquired from HAPI_GetAssetDefinitionParmCounts.
[in]	string_evaluate	Whether or not to evaluate the string expressions. 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]	string_values_array	Array of HAPI_StringHandle at least the size of string_length.
[in]	string_start	First index of range for string_values_array. Must be at least 0 and at most string_value_count - 1 acquired from HAPI_GetAssetDefinitionParmCounts.
[in]	string_length	Must be at least 0 and at most string_value_count - string_start acquired from HAPI_GetAssetDefinitionParmCounts.
[out]	choice_values_array	Array of HAPI_ParmChoiceInfo at least the size of choice_length.
[in]	choice_start	First index of range for choice_values_array. Must be at least 0 and at most choice_value_count - 1 acquired from HAPI_GetAssetDefinitionParmCounts.
[in]	choice_length	Must be at least 0 and at most choice_value_count - choice_start acquired from HAPI_GetAssetDefinitionParmCounts.

HAPI_DECL HAPI_GetAssetInfo	(	const HAPI_Session *	session,
		HAPI_NodeId	node_id,
		HAPI_AssetInfo *	asset_info
	)

Fill an asset_info struct from a 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]	asset_info	Returned HAPI_AssetInfo struct.

HAPI_DECL HAPI_GetAssetLibraryFilePath	(	const HAPI_Session *	session,
		HAPI_AssetLibraryId	asset_library_id,
		HAPI_StringHandle *	file_path_sh
	)

Gets the HAPI_StringHandle for the file path of a loaded asset library.

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]	asset_library_id	The HAPI_AssetLibraryId of the asset library.
[out]	file_path_sh	The returned HAPI_StringHandle of the asset's file path on disk.

HAPI_DECL HAPI_GetAssetLibraryIds	(	const HAPI_Session *	session,
		HAPI_AssetLibraryId *	asset_library_ids_array,
		int	start,
		int	length
	)

Gets the HAPI_AssetLibraryId's for HDAs that are loaded in Houdini.

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.
[out]	asset_library_ids_array	Array of HAPI_AssetLibraryId's at least the size of length.
[in]	start	First index from the list of HAPI_AssetLibraryId's to return. Must be at least 0 and at most count - 1 where count is the value returned by HAPI_GetLoadedAssetLibraryCount.
[in]	length	The number of HAPI_AssetLibraryId's to return. Must be at least 0 and at most count - start where count is the value returned by HAPI_GetLoadedAssetLibraryCount.

HAPI_DECL HAPI_GetAvailableAssetCount	(	const HAPI_Session *	session,
		HAPI_AssetLibraryId	library_id,
		int *	asset_count
	)

Get the number of assets contained in an asset library. You should call HAPI_LoadAssetLibraryFromFile() prior to get a library_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]	library_id	Returned by HAPI_LoadAssetLibraryFromFile().
[out]	asset_count	The number of assets contained in this asset library.

HAPI_DECL HAPI_GetAvailableAssets	(	const HAPI_Session *	session,
		HAPI_AssetLibraryId	library_id,
		HAPI_StringHandle *	asset_names_array,
		int	asset_count
	)

Get the names of the assets contained in an asset library.

The asset names will contain additional information about the type of asset, namespace, and version, along with the actual asset name. For example, if you have an Object type asset, in the "hapi" namespace, of version 2.0, named "foo", the asset name returned here will be: hapi::Object/foo::2.0

However, you should not need to worry about this detail. Just pass this string directly to HAPI_CreateNode() to create the node. You can then get the pretty name using HAPI_GetAssetInfo().

You should call HAPI_LoadAssetLibraryFromFile() prior to get a library_id. Then, you should call HAPI_GetAvailableAssetCount() to get the number of assets to know how large of a string handles array you need to allocate.

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]	library_id	Returned by HAPI_LoadAssetLibraryFromFile().
[out]	asset_names_array	Array of string handles (integers) that should be at least the size of asset_count.
[in]	asset_count	Should be the same or less than the value returned by HAPI_GetAvailableAssetCount().

HAPI_DECL HAPI_GetLoadedAssetLibraryCount	(	const HAPI_Session *	session,
		int *	count
	)

Gets the number of HDAs that have been loaded by Houdini.

Note

This only includes HDAs that have been loaded from disk. Embedded HDAs will be excluded.

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.
[out]	count	The returned number of loaded HDAs.

HAPI_DECL HAPI_LoadAssetLibraryFromFile	(	const HAPI_Session *	session,
		const char *	file_path,
		HAPI_Bool	allow_overwrite,
		HAPI_AssetLibraryId *	library_id
	)

Loads a Houdini asset library (OTL) from a .otl file. It does NOT create anything inside the Houdini scene.

Note

This is when we actually check for valid licenses.

The next step is to call HAPI_GetAvailableAssetCount() to get the number of assets contained in the library using the returned library_id. Then call HAPI_GetAvailableAssets() to get the list of available assets by name. Use the asset names with HAPI_CreateNode() to actually create one of these nodes in the Houdini scene and get back an asset_id.

Note

The HIP file saved using HAPI_SaveHIPFile() will only have an absolute path reference to the loaded OTL meaning that if the OTL is moved or renamed the HIP file won't load properly. It also means that if you change the OTL using the saved HIP scene the same OTL file will change as the one used with Houdini Engine. See Saving a HIP File.

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]	file_path	Absolute path to the .otl file.
[in]	allow_overwrite	With this true, if the library file being loaded contains asset definitions that have already been loaded they will overwrite the existing definitions. Otherwise, a library containing asset definitions that already exist will fail to load, returning a HAPI_Result of HAPI_RESULT_ASSET_DEF_ALREADY_LOADED.
[out]	library_id	Newly loaded otl id to be used with HAPI_GetAvailableAssetCount() and HAPI_GetAvailableAssets().

HAPI_DECL HAPI_LoadAssetLibraryFromMemory	(	const HAPI_Session *	session,
		const char *	library_buffer,
		int	library_buffer_length,
		HAPI_Bool	allow_overwrite,
		HAPI_AssetLibraryId *	library_id
	)

Loads a Houdini asset library (OTL) from memory. It does NOT create anything inside the Houdini scene.

Note

This is when we actually check for valid licenses.

Please note that the performance benefit of loading a library from memory are negligible at best. Due to limitations of Houdini's library manager, there is still some disk access and file writes because every asset library needs to be saved to a real file. Use this function only as a convenience if you already have the library file in memory and don't wish to have to create your own temporary library file and then call HAPI_LoadAssetLibraryFromFile().

The next step is to call HAPI_GetAvailableAssetCount() to get the number of assets contained in the library using the returned library_id. Then call HAPI_GetAvailableAssets() to get the list of available assets by name. Use the asset names with HAPI_CreateNode() to actually create one of these nodes in the Houdini scene and get back an asset_id.

Note

The saved HIP file using HAPI_SaveHIPFile() will contain the OTL loaded as part of its Embedded OTLs. This means that you can safely move or rename the original OTL file and the HIP will continue to work but if you make changes to the OTL while using the saved HIP the changes won't be saved to the original OTL. See Saving a HIP File.

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]	library_buffer	The memory buffer containing the asset definitions in the same format as a standard Houdini .otl file.
[in]	library_buffer_length	The size of the OTL memory buffer.
[in]	allow_overwrite	With this true, if the library file being loaded contains asset definitions that have already been loaded they will overwrite the existing definitions. Otherwise, a library containing asset definitions that already exist will fail to load, returning a HAPI_Result of HAPI_RESULT_ASSET_DEF_ALREADY_LOADED.
[out]	library_id	Newly loaded otl id to be used with HAPI_GetAvailableAssetCount() and HAPI_GetAvailableAssets().