The 3D models (PIDs or PlanetaryInteractiveDioramas) of entire cities developed and
under development by Ultramundum Foundation deliver extremely large urban areas for free
interactive exploration on a standard personal computer, with an extremely high level of
realism and realistic personal / veicular traffic.
PIDs are completely open source and their Tabulae (elements at the base of the
technology used) will be freely accessible and modifiable by everybody.
Until today, only portions of a city have been modeled with similar tecnologies,
because the data load for a model such this, with undhreds of thousands of buildings, has
ever been pohibitive. PIDs allows for interactive exploration on a standard personal
computer with a modern video card. Out-of-ordinary powerful computers are not necessary.
Thanks to the patented UltraPeg technology and the geographical Automatic Detail
geenrators, PIDs offer an interactive flight on all the city with the possibility of
descent to the ground level of any single street to walk amont he buildings. Getting
altitude the speed increases accordingly to allow for an exploration experience easy and
To create this kind of products, new software modules and procedures have been
developed, beyond the base procedural parametric technology UltraPeg based on Tabulae.
First, UltraPort supports the jerarchical cellular decomposition of the surface of
entire planets; this is achived with the PlanetSector system. It is composed by Tabulae
that are capable of automatically generate jearchical planetary surfaces, subdiving
progressively in subelements of the same type near the user's Avatar and so producing a
variable detail rpresentation of the entire celestial body. In this way, near the observer
the terrain appears extremely detailed and the resolution lowers toward the horizon, where
there are farther portions; the user-perceived resolution appears constant. An entire
planet can be explored interactively and appear highly detailed everywhere, even on low
power and memory PCs. The jerarchical PlanetSectors structure id dynamic: when the
observer moves, the PlanetSectors toward his direction subdivide in others more detailed,
while those at the back are substituted by thier lower-resolution ancestors. The resulting
structure is highly dynamic and automatically modifies itself when the Avatar moves,
producing entire star systems that allow any kind of trips.
A special debug mode can be activated to see the PlanetSector bounding boxes and
coordinates. The coordinate of each planet sector is made from 3 numbers: the PlanetSecor
level (0 for the entire planet, 1 for the emisphere, ...), the longitude and the latitude
in PlanetSectors form Greenwich and the South pole.
A special debug camera can fly independently of the Avatar position, so that views of
the PlanetSectors structure can be obtained. Without it, the system would continuously
update the scene to show a detailed view everywhere the Avatar moves.
An automatic generation is needed to visualize every building of a city with highly
realistic graphical details. Just think about the fact that a city like Turin has more
than one hundred thousands buildings and Rome has more that five hundred thousands: it is
clear that it is not possible to employ a human modeler, that would need an extremely
large number of work hours. The Automatic Buildings Generator is the answer to this
problem. It is a set of Tabulae that is capable of producing buildings from cartographic
data imported by the open source software UltraTools. Import is all about jerarchical
subdivision of the buildings set on the basis of the largest portion of the base on each
PlanetSector. Then an analisys module produces the estimated roof structure. All these
informations are inserted into a geographical database that is processed by the Automatic
Flowerbeds, like other portions of the environment, have details of the grass and not a
simple green surface. The open source importer UltraTools subdivides the polygons defining
every area (parks, rivers, boardwalks, cultivations) in portions that are
PlanetSectors-aligned. Semantic information (normally the type of usage of the ground) are
inserted into the resulting database. PlanetSectors generation Tabulae read the database
and call other Tabulae (called PlanetSectorProcessors) that generate the resulting visible
surface, without any human intervention. For instance, the park generating Tabula 'plant'
the grass and represent the ground as dirt with dry leaves to generate a believable
Other details, such as boardwalks borders, are generated by specific Tabulae called by
the PlanetSectorProcessors (for instance the boardwarlks generator). In the PlanetSector
system there are vector informations, not raster. This means that, for instance, the
boardwalks borders are not defined by pixels of the satellite imagery changing color,
inevitably blurred, but by precise lines (vectors) with spatial coordinates and
directions. The automatic detail generators can process structural informations, not more
or less blurred portions.
A powerful automatic traffic generation system, already available as an academic
research, can be inserted into the cellular-subdivided city structure. Veichles and people
walk around the streets and boardwalks to bring to life the entire city.
Any Tabula, the data structure at the root of Ultramundum Foundation's UltraPeg
technology, can hold multiple data types. For the Turin city model, informations on
buildings positions, root maps, olympic areas placements and specific schematics have been
imported from Autocad files and other databases.
The Autocad file importer, called UltraTools, allows for fast and almost automatic
acquisition of public databases, converted in a very short time to three-dimensional
elements. All these data can then be explored in real-time.
The Foundation can arrange interactive demonstrations on request, because this product
can not be freely distributed yet.