Interactivity

Contributors

• ISO/IEC SC29 WG3 (MPEG Systems) - Scene Description Breakout Group
• Contacts
  • Thomas Stockhammer (MPEG-I Scene Description BoG Chair, tsto@qti.qualcomm.com)

Status

Based on ISO/IEC DIS 23090-14 2nd Edition

Dependencies

Written against the glTF 2.0 spec.

Overview

Interactivity is supported at the scene level and at the node level through the definition of two extensions MPEG_scene_interactivity and MPEG_node_interactivity. When present, the MPEG_scene_interactivity extension shall be included as extension to the scene object. When present, the MPEG_node_interactivity extension shall be included as extension to a node object. The MPEG_node_interactivity extension is used to complement the interactivity extension defined at the scene level. One particular case is the definition of the parameters for a physics engine. That is, when an MPEG_node_interactivity extension contains a trigger of type TRIGGER_COLLISION without being referenced by a trigger of type TRIGGER_COLLISION at the MPEG_scene_interactivity extension, this node shall not be considered for collision detection and instead only be used by the physics engine.

Semantics

Semantics at scene level

Semantics at node level

Semantics at scene level

The semantic of the MPEG_scene_interactivity extension is based on the definition of trigger, action and behavior objects as shown in Table 1.

Table 1: Semantic of the MPEG_scene_interactivity extension

Name	Type	Required	Default	Description
triggers	MPEG_scene_interactivity.trigger [1-*]	✓ Yes		Contains the definition of all the triggers used in that scene.
actions	MPEG_scene_interactivity.action [1-*]	✓ Yes		Contains the definition of all the actions used in that scene.
behaviors	MPEG_scene_interactivity.behavior [1-*]	✓ Yes		Contains the definition of all the behaviors used in that scene. A behavior is composed of a pair of (triggers, actions), control parameters of triggers and actions, a priority weight and an optional interrupt action.
recommendedPhysicsHighPrecision	Boolean	No	false	Determines whether the application should enable a more deterministic and precise physic simulation
gravity	Number	No	-9.81	Determine the gravity for the whole scene. In meter per second square (m.s-2) as defined in the international unit system.
recommendedPhysicsFrameRate	Number	No	50	Provides the recommended frame rate at which the Physics Engine should operate. In frame per second as defined in the international unit system.
bounceThreshold	number	No	1	A contact with a relative velocity below this threshold will not result in a bounce. In meter per second (m.s-1) as defined in the international unit system.

The semantic of a trigger is provided in Table 2.

Table 2: Semantic of a trigger

Name	Type	Required	Default	Description
type	enumeration	✓ Yes		One element of Table 3 that defines the type of the trigger.
if (type == TRIGGER_COLLISION){
nodes	array	✓ Yes		Indices of the nodes in the nodes array to be considered for collision determination. Any detection of collision shall activate the trigger
primitives	array(Primitive)	No	N/A	List of primitives used to activate the proximity or collision trigger. Semantics of Primitive are presented in Table 4.
}
if (type == TRIGGER_PROXIMITY){
referenceNode	number	No	N/A	Index in the nodes array, of the node to consider for the proximity evaluation. In the absence of the referenceNode attribute, the active camera managed by the application shall be used.
distanceLowerLimit	number	No	0	Threshold minimum in meters for the proximity calculation, based on the distance between the nodes and the referenceNode.
distanceUpperLimit	number	✓ Yes		Threshold maximum in meters for the proximity calculation, based on the distance between the nodes and the referenceNode.
nodes	array	✓ Yes		Indices of the nodes in the nodes array to be considered. All the nodes shall have a distance from the origin of their local space to the referenceNode above the distanceLowerLimit and below the distanceUpperLimit to activate the trigger
primitives	array(Primitive)	No	N/A	List of primitives used to activate the proximity or collision trigger. Semantics of Primitive are presented in Table 4.
}
if (type== TRIGGER_USER_INPUT){
userInputDescription	string	✓ Yes		Describes the user body part and gesture related to the input. The format shall follow the OpenXR input path description as defined in [OpenXR] section 6. An example is: “/user/hand/left/grip”.
nodes	array	No	N/A	Indices of the nodes in the nodes array to be considered for this user input.
}
if (type== TRIGGER_VISIBILITY){
cameraNode	number	✓ Yes		Index to the node containing a camera in the nodes array for which the visibilities are determined. The visibility trigger shall be evaluated only if the related camera is active.
nodes	array	✓ Yes		Indices of the nodes in the nodes array to be considered. All the nodes shall be visible by the camera to activate the trigger.
}

Table 3: type of trigger

Trigger type	Description
TRIGGER_COLLISION=0	Collision Trigger
TRIGGER_PROXIMITY	Proximity Trigger
TRIGGER_USER_INPUT	User_Input Trigger
TRIGGER_VISIBILITY	Visibility Trigger

The semantics of a trigger primitive are defined in Table 9.

Table 4: Semantics of MPEG_scene_interactive.trigger.primitive properties

Name	Type	Required	Default	Description
type	enumeration	No	BV_SPHEROID	Describes the type of primitive used to activate the proximity trigger. The available options are: BV_CUBOID = 0, BV_PLANE_REGION = 1, BV_CYLINDER_REGION = 2, BV_CAPSULE_REGION = 3, BV_SPHEROID = 4 The default is BV_SPHEROID. Semantics are presented in Table 5.
boundary	number	No	0.0	Defines the region of intersection within the primitive. if zero, then all area of the primitive activates the trigger. Otherwise, the region of intersection decreases following the normal direction of all sides of the primitive from its centroid. For the capsule primitive, it should be applied over the radius, top, and base attributes.
transformationMatrix	array	No	[1.0,0.0,0.0,0.0, 0.0,1.0,0.0,0.0, 0.0,0.0,1.0,0.0, 0.0,0.0,0.0,1.0]	Floating-point 4x4 matrix that defines the initial orientation, translation, and scale of a primitive. Formatted in column-major order. The primitive shall follow x+ for width, y+ for height, z+ for length . The matrix transformation allows to transform any primitive after initialization.

Table 5: Semantical description of each primitive region

Name	Type	Required	Default	Description
if (type == BV_CUBOID) {
width	number	✓ Yes		Width of the box.
height	number	✓ Yes		Height of the box.
length	number	✓ Yes		Length of the box.
centroid	VEC3	✓ Yes		Centroid 3D coordinate (x,y,z) of the cube.
}
if (type == BV_PLANE_REGION) {
width	number	✓ Yes		Width of the plane.
height	number	✓ Yes		Height of the plane.
centroid	VEC2	✓ Yes		Centroid 2D coordinate (x,y) or (x,z) or (y,z) of the plane.
}
if (type == BV_CYLINDER_REGION) {
radius	number	✓ Yes		Radius of the cylinder.
length	number	✓ Yes		Length of the cylinder.
centroid	VEC3	✓ Yes		Centroid 3D coordinate (x,y,z) of the cylinder
}
if (type == BV_CAPSULE_REGION) {
radius	number	✓ Yes		Radius of the capsule.
baseCentroid	VEC3	✓ Yes		Centroid 3D coordinate (x,y,z) of the base semi-sphere of the capsule.
topCentroid	VEC3	✓ Yes		Centroid 3D coordinate (x,y,z) of the top semi-sphere of the capsule.
}
if (type == BV_SPHEROID) {
radius	number	✓ Yes		Radius of the sphere.
centroid	VEC3	✓ Yes		Centre 3D coordinate (x,y,z) of the sphere.
}

The semantic of an action is provided in Table 6.

Table 6: Semantic of action

Name	Type	Required	Default	Description
type	enumeration	✓ Yes		One element of Table 7 that defines the type of the action.
delay	number	No	0.0	Duration of delay in second before executing the action.
if (type== ACTION_ACTIVATE){
activationStatus	enumeration	✓ Yes		ENABLED=0: the node shall be processed by the application DISABLED =1: the node shall be skipped by the application.
nodes	array	✓ Yes		Indices of the nodes in the nodes array to set the activation status.
}
if (type== ACTION_TRANSFORM){
transform		✓ Yes		A 4x4 transformation matrix to apply to the nodes.
nodes	array	✓ Yes		Indices of the nodes in the nodes array to be transformed.
}
if (type== ACTION_BLOCK){
nodes	array	✓ Yes		Indices of the nodes in the nodes array to lock their related transforms.
}
if (type == ACTION_ANIMATION){
animation	number	✓ Yes		Index of the animation in the animations array to be considered.
animationControl	enumeration	✓ Yes		One element of Table 8 that defines the control of the animation.
}
if (type == ACTION_MEDIA){
media	number	✓ Yes		Index of the media in the MPEG_media array to be considered.
mediaControl	enumeration	✓ Yes		One element of Table 9 that defines the control of the media.
}
if (type == ACTION_MANIPULATE){
manipulateActionType	enumeration	✓ Yes		One element of Table 10 that defines the action manipulate type.
axis	array	No	Up	(x,y,z) coordinates of the axis used for rotation and sliding. These coordinates are relative to the local space created by the user input described in the userInputDescription. For example a “/user/hand/left/pose” user input trigger creates a local space attached to the user left hand.
userInputDescription	string	✓ Yes		Describe the user input related to the manipulation action. The format shall follow the OpenXR input path description as defined in [OpenXR] section 6. An example is: “/user/hand/left/aim/pose”.
nodes	array	✓ Yes		Indices of the nodes in the nodes array to be manipulated.
}
if (type == ACTION_SET_MATERIAL){
material	number	✓ Yes		Index of the material in the materials array to apply to the set of nodes.
nodes	array	✓ Yes		Indices of the nodes in the nodes array to set their material.
}
if (type == ACTION_HAPTIC){
hapticActionNodes	array(HapticActionNode)	✓ Yes		List of haptic action nodes as defined in Table 13.
}
if (type == ACTION_SET_AVATAR) {
avatarAction	string	✓ Yes		The avatarAction is a URN that uniquely identifies the avatar action. For the MPEG reference Avatar, a set of avatar actions and their respective URNs is defined in Table H.4.3.2 of Annex H. For example, the URN “urn:mpeg:sd:2023:avatar:actionslist/speech” referenced in Table H.4.3.2 of Annex H sets the optional attributes “microphone” and “media”. Considering only the boolean attribute “microphone”, the nodes in the node array will activate/deactivate their “microphone” ability accordingly when this action is launched.
nodes	array	✓ Yes		Indices of the nodes in the nodes array to launch their avatar actions.
}

Table 7: Type of action

Action type	Description
ACTION_ACTIVATE=0	Set activation status of a node
ACTION_TRANSFORM	Set transform to a node
ACTION_BLOCK	Block the transform of a node
ACTION_ANIMATION	Select and control an animation
ACTION_MEDIA	Select and control a media
ACTION_MANIPULATE	Select a manipulate action
ACTION_SET_MATERIAL	Set new material to nodes
ACTION_HAPTIC	Get haptic feedbacks on a set of nodes
ACTION_SET_AVATAR	Get avatar related actions

Table 8: Control of animation

Animation Control	Description
ANIMATION_PLAY=0	Play the animation from time 0 or from any other time provided by a control.
ANIMATION_PAUSE	Pause the animation
ANIMATION_RESUME	Resume the animation from the last pause position.
ANIMATION_STOP	Stop the animation

Table 9: control of media

Media Control	Description
MEDIA_PLAY=0	Play the media from time 0 or from any other time provided by a control.
MEDIA_PAUSE	Pause the media
MEDIA_RESUME	Resume the media from the last pause position.
MEDIA_STOP	Stop the media

Table 10: Action Manipulate Type

Action Manipulate Type	description
ACTION_MANIPULATE_FREE=0	The nodes follow the user pointing device and its rotation.
ACTION_MANIPULATE_SLIDE	The nodes move linearly along the provided axis by following the user pointing device.
ACTION_MANIPULATE_TRANSLATE	The nodes translate by following the user pointing device.
ACTION_MANIPULATE_ROTATE	The nodes rotate around the provided axis by following the user pointing device.
ACTION_MANIPULATE_SCALE	Performs a central scaling of the nodes by following the user pointing device.

The semantics of a behavior is provided in Table 11.

Table 11: semantic of behavior

Name	Type	Required	Default	Description
triggers	array	✓ Yes		Indices of the triggers in the triggers array considered for this behavior
actions	array	✓ Yes		Indices of the actions in the actions array considered for this behavior.
triggersCombinationControl	string	✓ Yes		Set of logical operations to apply to the triggers A ‘#’ indicates the trigger index, ‘&’ indicates a logical AND operation, ‘|’ a logical OR operation and ‘’ a NOT operation. Parenthesis are used to group some operations. Such a syntax may give the following string: “#1&#2|(#3&#4)”. An empty string is understood as a logical OR between all the triggers. A regex expression (https://json-schema.org/understanding-json-schema/reference/regular_expressions.html) is specified in the JSON schema to validate this string.
triggersActivationControl	enumeration	✓ Yes		Indicates when the combination of the triggers shall be activated for launching the actions. One element of Table 12 that defines when the combination of the triggers shall be activated for launching the actions.
actionsControl	enumeration	✓ Yes		Defines the way to execute the defined actions. SEQUENTIAL=0: each defined action is executed sequentially in the order of the actions array. PARALLEL=1: the defined actions are executed concurrently.
interruptAction	number	No	N/A	Index of the action in the actions array to be executed if the behavior is still on-going and is no more defined in a newly received scene update.
priority	number	No	0	Integer value defining the priority associated to the behavior When several behaviors are in concurrence to affect the same node(s) at the same time, the behavior having the highest priority value shall be processed. The lower priority behavior(s) shall not be processed. In the case of behaviors having the same priority, the application should apply its own criteria.

Table 12:Trigger Activation Control

Trigger Activation Control	Description
TRIGGER_ACTIVATE_FIRST_ENTER=0	Activated when the conditions are first met
TRIGGER_ACTIVATE_EACH_ENTER	Activated each time the conditions are first met
TRIGGER_ACTIVATE_ON	Activated as long as the conditions are met
TRIGGER_ACTIVATE_FIRST_EXIT	Activated when the conditions are first no longer met
TRIGGER_ACTIVATE_EACH_EXIT	Activated each time the conditions are no longer met
TRIGGER_ACTIVATE_OFF	Activated as long as the conditions are not met

Table 13: Semantic of HapticActionNode object

Property	Type	Required	Default	Description
node	integer	✓ Yes		Identifier of the node in the glTF nodes array.
hapticObject	integer	No	N/A	Index to a haptic object in the hapticObjects array of the MPEG_haptic extension.
actionLocation	integer	No	0xFFFFFFFF	Body part mask specifying where on the body the signal can be rendered. Possible values are detailed in Table 17.
washout	boolean	No	False	Specifies whether the action should trigger a washout (reset to the origin) of the associated devices.
useCollider	boolean	No	False	Used with a Collision trigger. If True, the rendering engine shall use collision information to estimate the desired location of the haptic feedback on the body. For haptic materials, the presentation engine retrieves the associated haptic texture media and generates haptic feedback based on texture information and collision position. If false, the signal shall be rendered based on the information specified in the Haptic file.
materialHapticModality	array(enumeration)	No	N/A	List of haptic material modalities that shall be rendered. Possible values are detailed in Table 16.
hapticActionMedias	array(HapticActionMedia)	✓ Yes		List of Haptic Action Media.

Table 14: Semantic of the HapticActionMedia object

Property	Type	Required	Default	Description
mediaIndex	integer	✓ Yes		Index in the accessors array of the associated haptic data.
perceptionIndices	array(integer)	✓ Yes		Indices of the perceptions of the media that shall be rendered. If the list if empty all perceptions shall be rendered
hapticModality	array(enumeration)	No	N/A	List of haptic modalities that can be rendered. Possible values are described in Table 15.
hapticControl	enumeration	No	HAPTIC_PLAY	One element of Table 49 that defines the control of the haptic rendering.
loop	boolean	No	False	Specifies if the haptic rendering of the data should be continuously looping.

Table 15: List of haptic modalities

Pressure = 0
Acceleration
Velocity
Position
Temperature
Vibrotactile
Water
Wind
Force
Electrotactile
Vibrotactile Texture
Stiffness
Friction
Other

Table 16: List of haptic Material Modalities

Stiffness = 0
Friction
Vibrotactile Texture
Temperature
Vibration
Custom

Table 17: Body part masks

	Name	Body_part_mask (binary)	Hexadecimal	Decimal
0	Unspecified	00000000000000000000000000000000	0x00000000	0
1	Head Face	00000000000000000000000000000001	0x00000001	1
2	Head Back/Neck/Ears	00000000000000000000000000000010	0x00000002	2
3	Mouth Bag	00000000000000000000000000000100	0x00000004	4
4	Lower Jaw	00000000000000000000000000001000	0x00000008	8
5	Upper Jaw	00000000000000000000000000010000	0x00000010	16
6	Eye Left	00000000000000000000000000100000	0x00000020	32
7	Eye Right	00000000000000000000000001000000	0x00000040	64
8	Chest Front	00000000000000000000000010000000	0x00000080	128
9	Chest Back	00000000000000000000000100000000	0x00000100	256
10	Upper Arm Left	00000000000000000000001000000000	0x00000200	512
11	Lower Arm Left	00000000000000000000010000000000	0x00000400	1 024
12	Hand Left	00000000000000000000100000000000	0x00000800	2 048
13	Upper Arm Right	00000000000000000001000000000000	0x00001000	4 096
14	Lower Arm Right	00000000000000000010000000000000	0x00002000	8 192
15	Hand Right	00000000000000000100000000000000	0x00004000	16 384
16	Abdomen Front	00000000000000001000000000000000	0x00008000	32 768
17	Abdomen Back	00000000000000010000000000000000	0x00010000	65 536
18	Upper Leg Left	00000000000000100000000000000000	0x00020000	131 072
19	Lower Leg Left	00000000000001000000000000000000	0x00040000	262 144
20	Foot Left	00000000000010000000000000000000	0x00080000	524 288
21	Upper Leg Right	00000000000100000000000000000000	0x00100000	1 048 576
22	Lower Leg Right	00000000001000000000000000000000	0x00200000	2 097 152
23	Foot Right	00000000010000000000000000000000	0x00400000	4 194 304
24-32	Reserved	00000000010000000000000000000000 - 10000000000000000000000000000000	0x00800000 -0x80000000	8 388 608 - 2 147 483 648

Table 18: Examples of body part combinations

Name	Body_part_mask (binary)	Hexadecimal	Decimal
Right arm	00000000000000000111000000000000	0x00007000	28 672
Left arm	00000000000000000000111000000000	0x00000E00	3 584
Right leg	00000000011100000000000000000000	0x00700000	7 340 032
Left leg	00000000000011100000000000000000	0x000E0000	917 504
Upper body	00000000000000011111111111111111	0x0001FFFF	131 071
Lower body	00000000011111100000000000000000	0x007E0000	8 257 536
Full body	11111111111111111111111111111111	0xFFFFFFFF	4 294 967 295

Table 19: List of Haptic controls

Haptic Control	Description
HAPTIC_PLAY = 0	Start the rendering of the haptic data from time 0 or from any other time provided by a control
HAPTIC_PAUSE	Pause the rendering of the haptic data
HAPTIC_RESUME	Resume the rendering of the haptic data from the last pause position.
HAPTIC_STOP	Stop the rendering of the haptic data

Semantics at node level

In complement to the interactivity objects defined in the glTF scene-level extension, some additional data could be provided at the level of the affected glTF nodes to specialize the trigger activation. The semantic of the MPEG_node_interactivity extension is shown in Table 50.

Table 20: Semantic of the MPEG_node_interactivity extension

Name	Type	Required	Default	Description
triggers	array	✓ Yes		Array of node triggers (as defined in Table 21). Only distinct types are allowed. The minimum size of this array is 1, and the maximum size is size of trigger types as defined in this specification.

Table 21: Semantic of the MPEG_node_interactivity.trigger extension

Name	Type	Required	Default	Description
type	enumeration	✓ Yes		One element of Table 3 that defines the type of the trigger.
if (type == TRIGGER_COLLISION){
collider	integer	✓ Yes		the index of the mesh element that provides the collider geometry for the current node. The collider mesh may reference a material.
isStatic	boolean	✓ Yes		If True, the collider is defined as a static collider.
usePhysics	boolean	✓ Yes		Indicates if the object shall be considered by the physics simulation.
if (usePhysics) {
needPreciseCollisionDetection	Boolean	No	false	If true, the physics engine should handle the collision detection more accurately by increasing the detection rate for this node.
linearDamping	Number	No	0	A non-negative value, in second-1 (s-1), as defined in the international unit system. It defines the linear drag coefficient which corresponds to the rate of decrease of the linear velocity over time. It is used to compute a new velocity value V(t) at each simulation step (dt): V(t+dt) = V(t)(1-linearDampingdt), the velocity being clamped to 0.
angularDamping	number	No	0	A non-negative value, in second-1 (s-1), as defined in the international unit system. It defines the angular drag coefficient which corresponds to the rate of decrease of the angular velocity over time. It is used to compute a new velocity value V(t) at each simulation step (dt): V(t+dt) = V(t)(1-angularDampingdt), the velocity being clamped to 0.
useGravity	boolean	✓ Yes		Indicates if the gravity affects the object
mass	number	✓ Yes		Mass of the object in kilogram as defined in the international unit system..
restitution	number	✓ Yes		Provides the ratio of the final to initial relative velocity between two objects after they collide.
staticFriction	number	✓ Yes		Unitless friction coefficient as defined in the Coulomb friction model. Friction is the quantity which prevents surfaces from sliding off each other. StaticFriction is used when the object is lying still. It will prevent the object from starting to move.
dynamicFriction	number	✓ Yes		Unitless friction coefficient as defined in the Coulomb friction model. When a large enough force is applied to the object, the dynamicFriction is used, and will attempt to slow down the object while in contact with another.
}
primitives	array(Primitive)	No	N/A	List of primitives used to activate the proximity or collision trigger. Semantics of Primitive are presented in Table 9.
}
if (type == TRIGGER_PROXIMITY){
allowOcclusion	boolean	✓ Yes		Indicates if occlusion by other nodes should be considered
upperDistanceWeight	number	No	1	The weight applied to the distanceUpperLimit parameter defined at scene level
lowerDistanceWeight	number	No	1	The weight applied to the distanceLowerLimit parameter defined at scene level
primitives	array(Primitive)	No	N/A	List of primitives used to activate the proximity or collision trigger. Semantics of Primitive are presented in Table 9.
}
if (type ==TRIGGER_USER_INPUT){
userInputParameters	array	✓ Yes		Provides additional information related to the user inputs (eg “max speed = 0.5”)
}
if (type== TRIGGER_VISIBILITY){
allowsPartialOcclusion	boolean	✓ Yes		The visibility computation shall take into account both the occultation by other node(s) and the camera frustrum. If the allowsPartialOcclusion Boolean is TRUE, then a partial visibility of this node activates the trigger. If the allowsPartialOcclusion Boolean is FALSE, then this node shall be fully in the camera frustrum and not be occluded by any other node(s) except the nodes listed in the nodes array to activate the trigger.
nodes	array	No	N/A	Set of nodes that shall not be considered for the visibility computation, when the allowsPartialOcclusion is FALSE.
mesh	number	No	N/A	Index of the mesh in the scene meshes array that will be used to compute visibility.
}

Processing model

When a scene description file becomes available, the Presentation Engine

• parses the related glTF file
• creates each behavior composed of triggers and actions described at the interactivity scene level extension
• specializes the trigger for each affected node with the additional data provided at the interactivity node level extension if present At runtime, the presentation Engine iterates on each behavior and performs the following tasks:
• checks the activation status of each trigger of this behavior by following the procedure detailed in the figure below,
• checks the logical combination of these trigger status,
• if this status satisfies the triggersActivationControl value, launches the corresponding actions.

When several behaviors are in concurrence to affect the same node(s) at the same time, the behavior having the highest priority value shall be processed. The lower priority behavior(s) shall not be processed. In the case of behaviors having the same priority, the application should apply its own criteria. When a new scene description update is received, the application follows the procedure detailed in the figure below. An on-going behavior corresponds to a behavior:

• having its triggers status verifying the triggersActivationControl value for that frame,
• or having previously launched a play action related to a media/animation,
• or having previously launched an action with a delay not yet expired. To check if the behavior is still defined, the application should check if the scene description update leads to:
• removal of this behavior in the behaviors array.
• modification of any parameter of this behavior (e.g. by adding a new trigger, by changing the trigger activation control,…).
• removal of any of the referenced nodes by the action. The application shall process the interrupt action only if the timing requirement of the scene description update is met.

If the scene description document contains a description of physics properties based on another physics model, then that physics model shall take precedence in the processing of the scene.

Otherwise, the application shall handle a physics simulation if the usePhysics Boolean is TRUE on any of the collision trigger extensions defined at the node level. When a collision occurs between two nodes, the application should calculate the combination of the restitution, static friction and dynamic friction values based on the values provided by the collision trigger extension of the two nodes.

Schema

• JSON schema: MPEG_scene_interactivity.schema.json
• JSON schema: MPEG_node_interactivity.schema.json

Known Implementations

• ISO/IEC WD 23090-24

Resources

• ISO/IEC FDIS 23090-14, Information technology — Coded representation of immersive media — Part 14: Scene Description
• ISO/IEC WD 23090-24, Information technology — Coded representation of immersive media — Part 24: Conformance and Reference Software for Scene Description for MPEG Media

License

Copyright ISO/IEC 2022

The use of the "MPEG scene description extensions" is subject to the license as accessible here: https://standards.iso.org/ and is subject to the IPR policy as accessible here: https://www.iso.org/iso-standards-and-patents.html.