Develop the Schema for Objects

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While the location class stores all immobile objects we need an object class to store mobile objects. Of course the border between immobile locations and mobile objects is fluent. A chair will often be moved to other positions, a table may be moved a little bit after cleaning the floor and a heavy wardrobe normally isn't moved at all. If you want to read again about the details of mobile objects go back to the chapter Motivation.

Let's define the classes for mobile objects and object concepts. Add to the main method in our CreateDBSchema class:

OrientVertexType objectConcept = db.createVertexType("ObjectConcept", namedVertex); // Object types like cup, plate, table, ...
OrientVertexType mobileObject = db.createVertexType("MobileObject", namedVertex); // Real Objects like the red cup with the little crack
mobileObject.createProperty("Path_to_Image", OType.STRING); // Path to image file

For each mobile object we want to store its size as surrounding cuboid with length, width and height. To connect these three dimensions we can reuse the Coordinates class. Since Coordinates is an abstract class first a concrete subclass has to be created: Size3D. Each mobile object then gets an embedded Size property of type Size3D.

OrientVertexType size3D = db.createVertexType("Size3D", coordinate); // The abstract class coordinate is used to store sizes of objects
mobileObject.createProperty("Size", OType.EMBEDDED, size3D); // Size of an object with x > y and z = height in the object's default position

At last we define the edge classes. Since we already have defined the IS_A and IS_PART_OF edge classes for locations we only need to add the edge class PROB_IS_AT which stores the probability of an object being at a location, position or in/on/at another object. Therefore this edge class has some sort of probability as a property. In fact not a probability but a score is stored. If we used a probability we would have to guarantee that the sum of all probabilities for a mobile object is 1 when one probability is changed. This could be a time consuming operation. In contrast score values can be changed independently. Additionally a height may be stored as information at which level an object can be found e. g. in a cupboard or on a shelf.

OrientEdgeType prob_is_at = db.createEdgeType("PROB_IS_AT");
prob_is_at.createProperty("Score", OType.FLOAT).setMin("0").setMandatory(true).setNotNull(true);
prob_is_at.createProperty("Height", OType.FLOAT); // Height above floor for robot's linear drive

Finally the database connection is closed.

db.shutdown();
factory.close();

Now you can execute your program. Afterwords you can control the created schema using Studio or Console.