The Vision of a RealWorld Simulator - Programming GPS and OpenStreetMap Applications with Java - page 15

Chapter 2

The Vision of a
Real-World Simulator

2.1 Introduction

Chapter 1 compared the functionality of objects to devices, machines, and
other physical entities. With the separation of application and object
development, we derive a vision in this chapter to develop real-world objects
and to place them in (various) real-world applications in order to improve
their flexibility and robustness.
The vision will provide a guideline for the remainder of the topic and
beyond. The goal is to reverse the analogy of software objects and phys-
ical objects by implementing real-world objects as independent \things"
and to optimize them for different environments. In other words, we put
the object-oriented (OO) promises to the ultimate test by developing vir-
tual objects. A combination of different real objects should work without
restrictions and reflect the real world in a virtual reality.

2.2 Physical Objects

The little gravity application described in Section 1.4.1 creates masses
to interact with each other. Its main function represents the external
environment|the gravity eld and a coordinate system to relate the masses
to each other. The objects behave according to their internal mathemati-
cal world model, based on the provided or perceived external information.
External and internal development represent two different perspectives on
the same world. Simulating the concept of inertia, a MassObject requires
the attributes mass , position , and speed .
For a physicist a model is realistic if it makes the correct predictions
according to the real-world behavior perceived in experiments. Different
MassObject s can implement different mathematical operations and still in-
teract with one other. To allow for experimentation in simulations, it is
helpful to separate the environment from the objects. By checking on the

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