Download Improvements in an Interactive Traffic and Driving Simulator for

An attempt to improve the performance of NIOBE was to substitute the current
street - that uses several textures - by a new street that contains just one texture.
Analysing the results, one should notice a significant improvement in the framerate
average. Nevertheless, an important factor is the minimum framerate as well, and the
new street proved to be worse than the current street when considering the distribution
of minimum framerates during the simulation. Hence, this solution was rejected and
the current street was kept.
One of the main problems during the initial stage of the driving simulation was the
way that NIOBE updates the dynamic objects (vehicles). The responsible element for
the physical events of the simulation is the application PELOPS, which sends to NIOBE
messages through the network that contains information of where the vehicles must be
located. So far, NIOBE just updated the vehicles position using the raw values stored
in these messages. The result was a terrible trembling in the vehicle movements. After
a mathematical treatment that considers the time clock of NIOBE machine and the
time stamp of each position received, the vehicles’ movements are now smooth and
realistic.
Prior to simulation, there is an important phase that aims to build the scenarios.
A scenario is constituted by a street and objects surrounding it. To build the street and
include the objects in the virtual world, the modelers, who are responsible to create
the scenarios, must use the application Roadcraft. This stage of the project demands
a long time to be concluded, since the scenarios for testing contains motorways with
more than 50 kilometers. For this reason, several functionalities were implemented to
accelerate and facilitate their work.
One of those functionalities that speeded up the construction of the scenarios
is the implementation of the real outline for the objects viewed in Roadcraft. As the
old outlines usually were a rectangle that involves the object, consequently, it was hard
to locate correctly the objects in the world. Besides that, the modelers should use
NIOBE as editor, and move the objects in a 3D environment. With the real outline
of the objects, the modelers rarely need NIOBE to adjust them, only when the object
requires to be rotated on the angle that is not possible using Roadcraft, since it allows
just one rotation direction.
Considering now the simulation running, several tools are used for monitoring,
controlling, recording and playing. The VirtualFIS showed an important tool to evaluate
the state of the convoy, as well as a monitoring tool due to the new map module imple-
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