Let’s try a few definitions…………
Reality, Virtual Reality, Real Reality
There is only one reality, but every person carries an own model of the reality in his mind.
This model helps the person to foresee the future development of reality and it helps the person to influence reality according to his will.
Virtual reality is a part of the reality that is implemented by means of technology and that helps one or more persons (see user) to inhabit a virtual scene that needs not be directly related to the reality.
Strictly spoken, an ancient form of virtual reality is already to sit around the camp fire telling stories. Also books and movies form kinds of virtual reality.
Usually we use the narrow term virtual reality, if some minimum technological requirements are fulfilled, e.g. the usage of stereoscopic computer graphics.
We use the term real reality to denote all parts of the reality that are not part of the virtual reality in question, but that are of relevance for the virtual reality.
Anything else is just reality.
A user is a person who uses a personal scene instance (see below) to inhabit a Simple Multiuser Scene (see below) in the course of a multiuser session (see below).
Personal Scene Instance (PSI)
A personal scene instance is the collection of all technological facilities that are needed so that one user can inhabit a Simple Multiuser Scene.
One important facility of the PSI can be a Web3D browser that interprets a concrete scene graph.
The user interface of the PSI can be used via the senses and skills (SaSk) of the user.
Simple Multiuser Scene (SMS)
A Simple Multiuser Scene is a collection of facilities that are accessible via the 3D Web and that can be instantiated within PSIs to provide virtual senses and skills (vSaSk) to users.
Such facilities include, e.g. (see below for detailed definitions):
- Avatars to be able to represent virtual identies
- Models to be able to render the renderable objects of the scene
- Modules to be able to render the surroundings of the scene
- Geographic infrastructure to be able to render the surroundings of the scene
A multiuser session is an instantiation of an SMS for a concrete set of users.
Those users will be able to inhabit the virtual scene together.
Technically spoken, a multiuser session is a collection of one or more PSIs and of one optional SCSI (see below), all of which are synchronized to each other.
Server/Controller Scene Instance (SCSI)
The Server/Controller Scene Instance connects the multiuser session to the real reality in order to synchronize real life facilities (see below) with virtual life facilities (see below).
This enables the mixed reality mode to be used as operational mode (see below).
Virtual Life Facility (VLF)
Virtual life facilities are used to provide virtual senses and skills to a user. In mixed reality mode VLFs may be synchronized to real life facilities (see below).
A VLF is an instantiation of a facility of the SMS.
Examples of VLFs are:
- Virtual life avatars (or simply avatars) to represent virtual identities to one user
- Models to render the renderable objects of the scene to one user
- Modules to render the surroundings of the scene to one user
- Geographic infrastructure to render the surroundings of the scene to one user
Real Life Facility (RLF)
Real life facilities are parts of the real reality.
We distinguish following kinds of RLFs: real life avatars (see below), real life objects (see below) and collateral entities (see below).
Operational Modes (OM)
A multiuser session can operate in one of following modes:
- Single user mode – only one PSI exists, SCSI does not exist
- Multi user mode – more than one PSI exist, SCSI does not exist
- Mixed reality mode – at least one PSI exists, SCSI exists
Model, Real Life Object (RLO)
A model is an object within an SMS that can be rendered.
In other words, it is an object to the virtual senses and skills of the user, when he inhabits the SMS through the PSI.
In mixed reality mode, a model may represent a real life object (RLO).
An RLO is always represented by a model, otherwise it would be a collateral entity.
Avatar, Virtual Life Avatar (VLA), Real Life Avatar (RLA)
An avatar is an object that represents a virtual identity (see below). A virtual life avatar is a model that represents a virtual identity and a real life avatar is an RLO that represents a virtual identity.
Collateral Entity (CE)
A collateral entity is an RLF that is not an RLO. I.e. it is a real life facility that is somehow relevant for the multiuser session, but it is not modelled in the SMS.
Module, Universal Positioning System (UPS)
According to the MMF paradigm, an SMS consists of one or more modules that build the surroundings of the scene, whereas each renderable object (each model) is assigned to one of the modules.
A module spans a local (pseudo-) euclidean spacetime, which is used to position the models.
In mixed reality mode, we will often use WGS84 coordinates as global coordinates, which can be used to position the modules.
Hence a local coordinate system in real reality can be defined relative to GPS coordinates.
Now the SMUOS framework aims to be a framework for the 21st century and hence a GPS will not be enough. We will need something that includes the universe into its concepts, not only the globe.
UPS the right wording for such idea.
And it need to be hierarchical, according to the eMMF paradigm. One level of modules being the top level (within a scene) containing top level models. Each top level model may contain second level modules containing second level models and so on.
Clear, there is nothing like a „top“ level in universe (in UPS), Hence the top level must be identified by gravitational field instead of velocity and position. This is ffs.
Geographic Infrastructure, Tiles
The relations among modules, geographic infrastructure and tiles are ffs.
Identity, Virtual Identity, Real Identity
Need not be defined. If we need to explain this, then we do really have a problem.
SrrTrains uses the Network Sensor / Event Stream Sensor for synchronization of scene instances.
The objects that are used within PSIs and within the SCSI to synchronize the multiuser session, are called MIDAS Objects (Multiuser Interactivity Driven Animation and Simulation Objects).
The SCSI can be seen as relay between MIDAS Objects and the Internet of Things (IoT), where we define POIs (see below) as the peers of the SCSI, when it relays the IoT into the multiuser session.
Point of Interaction, Point of Interest (POI)
A POI is a unit that can be addressed within the IoT.
A Point of Interest delivers a stream of events to the multiuser session. This stream describes (a part of) the state of one or more RLOs.
A Point of Interaction accepts a stream of events from the multiuser session. This stream influences (a part of) the state of one or more RLOs.
A Point of Interaction may deliver a stream of events to the multiuser session. This stream describes (a part of) the state of one or more RLOs.
Connectivity Platform (CP)
X3D scenes communicate with Collaboration Servers (CS) through Network Sensors / Event Stream Sensors. CP is a conceptual name for an evolved CS.