Live Session Management#

High-level Live Session operations that work across all storage backends (Nucleus, S3, Azure, HTTP). These functions provide session, layer, and user management for real-time collaboration. Live layer URLs are derived client-side by appending the layer name to the session URL: liveLayerUrl = sessionUrl + "/" + liveLayerName.

Enumerations Summary#

OmniClientLiveSessionEventType: Live session event types.

Functions Summary#

OmniClientRequestId omniClientLiveCreateSession(const char *baseLayerUrl, const char *sessionName, void *userData, OmniClientLiveCreateSessionCallback callback): Create a new Live Session.
OmniClientRequestId omniClientLiveJoinSession(const char *sessionUrl, const char *appName, void *userData, OmniClientJoinLiveSessionCallback eventCallback): Join a session to receive user presence events.
OmniClientRequestId omniClientLiveListSessions(const char *baseLayerUrl, void *userData, OmniClientLiveListSessionsCallback callback): List all Live Sessions for a base layer.
OmniClientRequestId omniClientLiveSendMessage(OmniClientRequestId sessionId, struct OmniClientContent *content, void *userData, OmniClientLiveSendMessageCallback callback): Send a message to all users in a session.

Structs Summary#

OmniClientLiveSessionEvent: Live session event structure.
OmniClientLiveSessionInfo: Information about a Live Session.
OmniClientLiveUserInfo: Information about a user in a Live Session.

Typedefs Summary#

OmniClientJoinLiveSessionCallback: Called when a live session event occurs.
OmniClientLiveCreateSessionCallback: Called with the result of omniClientLiveCreateSession .
OmniClientLiveListSessionsCallback: Called with the result of omniClientLiveListSessions .
OmniClientLiveSendMessageCallback: Called with the result of omniClientLiveSendMessage .

Enumerations#

enum OmniClientLiveSessionEventType#

Live session event types.

Values:

enumerator eOmniClientLiveSessionEvent_Connection#: Connected or disconnected (depending on result code)

enumerator eOmniClientLiveSessionEvent_Joined#: A user joined the session.

enumerator eOmniClientLiveSessionEvent_Left#: A user left the session.

enumerator eOmniClientLiveSessionEvent_Message#: A user sent a message.

Functions#

OmniClientRequestId omniClientLiveCreateSession( const char *baseLayerUrl, const char *sessionName, void *userData, OmniClientLiveCreateSessionCallback callback, )#

Create a new Live Session.

Creates a new live session for collaborative editing of a USD layer. The session URL is assigned by the system and may be predictable (Nucleus) or unpredictable (Storage API backends).

Parameters:

baseLayerUrl – URL of the base USD layer
sessionName – User-defined session name (must be unique per base layer)
userData – User data passed to callback
callback – Called with the created session URL

Returns:

Request ID that can be used with omniClientStop

OmniClientRequestId omniClientLiveJoinSession( const char *sessionUrl, const char *appName, void *userData, OmniClientJoinLiveSessionCallback eventCallback, )#

Join a session to receive user presence events.

The first event delivered to eventCallback will be eOmniClientLiveSessionEvent_Connection containing this client’s connection ID, which is needed for tagging user-specific objects in the scene (e.g., avatars).

If the underlying stream is reset (e.g. by an ingress controller), it is re-established transparently. A new eOmniClientLiveSessionEvent_Connection event is delivered with a potentially different connection ID. The peer list is diffed: peers present before and after the reconnect produce no additional Joined/Left events; only genuinely new or departed peers trigger callbacks.

To leave the session, call omniClientStop with the returned session ID.

Parameters:

sessionUrl – Session URL
appName – Application name to identify this client
userData – User data passed to callback
eventCallback – Called for user events (ack/joined/left/message)

Returns:

Session ID (use for leaving via omniClientStop and for omniClientLiveSendMessage)

OmniClientRequestId omniClientLiveListSessions( const char *baseLayerUrl, void *userData, OmniClientLiveListSessionsCallback callback, )#

List all Live Sessions for a base layer.

This is a simple request/response operation. To detect session changes, poll this function periodically (e.g., every 5-10 seconds).

Parameters:

baseLayerUrl – URL of the base USD layer
userData – User data passed to callback
callback – Called with list of sessions

Returns:

Request ID that can be used with omniClientStop

OmniClientRequestId omniClientLiveSendMessage( OmniClientRequestId sessionId, struct OmniClientContent *content, void *userData, OmniClientLiveSendMessageCallback callback, )#

Send a message to all users in a session.

You must have called omniClientLiveJoinSession first and use the returned session ID.

Parameters:

sessionId – Session ID from omniClientLiveJoinSession
content – The message content to send (ownership is transferred)
userData – User data passed to callback
callback – Called when send is complete

Returns:

Request ID that can be used with omniClientStop

Typedefs#

typedef void (*OmniClientJoinLiveSessionCallback)(void *userData, OmniClientResult result, OmniClientLiveSessionEvent const *event)#

Called when a live session event occurs.

Param userData:: User data passed to the function
Param result:: Result code indicating success or failure
Param event:: Live session event information

typedef void (*OmniClientLiveCreateSessionCallback)(void *userData, OmniClientResult result, const char *sessionUrl)#

Called with the result of omniClientLiveCreateSession.

Param userData:: User data passed to the function
Param result:: Result code indicating success or failure
Param sessionUrl:: System-assigned session URL (null if failed)

typedef void (*OmniClientLiveListSessionsCallback)(void *userData, OmniClientResult result, uint32_t sessionCount, OmniClientLiveSessionInfo const *sessions)#

Called with the result of omniClientLiveListSessions.

Param userData:: User data passed to the function
Param result:: Result code indicating success or failure
Param sessionCount:: Number of sessions in the sessions array
Param sessions:: Array of session information structures

typedef void (*OmniClientLiveSendMessageCallback)(void *userData, OmniClientResult result)#

Called with the result of omniClientLiveSendMessage.

Param userData:: User data passed to the originating function
Param result:: The result of the operation