The ARSM Model (Modeling Interactive Augmented Reality Environments) (Interactive 3D Multimedia Content) Part 2

Scene, Virtual, and Real AR-Classes

Containment relationships of an AR-Class are stored in the Cont set. The Relationships can refer to Virtual, Real, and Scene AR-Classes. The set of containment relationships Cont of an AR-Class is a union of three disjoint subsets:

where:

VCont denotes the set of containment relationships to Virtual AR-Classes, RCont denotes the set of containment relationships to Real AR-Classes, SCont denotes the set of containment relationships to Scene AR-Classes.

An AR-Class is a Virtual AR-Class if and only if:

If VCont = 0, then the AR-Class is a compound Virtual AR-Class that contains at least one containment relationship to a Virtual AR-Class. Otherwise, it is a simple Virtual AR-Class.

An AR-Class is a Real AR-Class if and only if:

If RCont = 0, then the AR-Class is a compound Real AR-Class that contains at least one containment relationship to a Real AR-Class. Otherwise, it is a simple Real AR-Class.

An AR-Class is a Scene AR-Class if and only if:

If SCont = 0, then the Scene AR-Class is a compound Scene AR-Class that contains at least one containment relationship to an embedded Scene AR-Class. Otherwise, it is a simple Scene AR-Class.

Modeling AR-Objects AR-Object

An AR-Object is a 5-tuple {oName, ocName, vId, vParentId,C), where:

oName is the name of the AR-Object,

ocName is the name of the AR-Class of the AR-Object,

vId is the identifier of the AR-Object,

vParentId is the parent AR-Object identifier,

C is the content of the AR-Object.

The oName element specifies an alphanumeric string that uniquely identifies the AR-Object in the R repository. The ocName element specifies the name of the AR-Class that the AR-Object is instantiated from. The vId element specifies the unique identifier of the AR-Object in an augmented reality scene. This element in Persistent AR-Objects is set to null. In the content use phase, the element is set to a valid value. The vParentId element specifies the identifier of the parent AR-Object in an augmented reality scene. The parent AR-Object is the one to which the AR-Object is attached to. This element in Persistent AR-Objects is set to null. In the content use phase, vParentId is initialized with the identifier of the containing AR-Object. While the content use phase progresses, the parent identifier can change to other AR-Objects contained in the augmented reality scene. The content C is a set of attribute values describing characteristics of the AR-Object. Each attribute value specifies a value for the corresponding attribute defined in the AR-Class.

An attribute value is a pair {avName, avValue), where:

avName is the attribute name, avValue is the actual attribute value.

The avName element specifies the name of the corresponding attribute defined in the AR-Class. Let av be an attribute value, then NV(av) denote the name of the corresponding attribute. The actual value to be assigned to the attribute is specified in the avValue element. The value must conform to the attribute type declared in the AR-Class. If the corresponding AR-Class has n attributes, then the content of the AR-Object is defined as follows:

where:

av1,…, avn denote the attribute values of the AR-Object.

Let avi denote an attribute value related to an attribute ai, then:

Attribute values may be either:

• property values—defining the values of properties of an AR-Object, or

• relationships—defining the relationships of an AR-Object to other AR-Objects. The set of attribute values C of an AR-Object is a union of three disjoint subsets:

where:

PropV denotes the set of property values of the AR-Object, such that:

CompV denotes the set of composition relationship values of the AR-Object, such that:

ContV denotes the set of containment relationship values of the AR-Object, such that:

Scene, Virtual, and Real AR-Objects

Containment relationships of an AR-Object are stored in the ContV set. The relationship values can refer to Virtual, Real, and Scene AR-Objects. The set of containment relationship values ContV of an AR-Object is a union of three disjoint subsets:

where:

VContV denotes the set of relationships to Virtual AR-Objects, such that:

RContV denotes the set of relationships to Real AR-Objects, such that:

SContV denotes the set of relationships to AR-Scenes, such that: