3D
modeling of paleolithic tools
Workshop on Archaeology and Computers, Vienna (Austria), 3-4 November 2004.
The
use of 3D models for registration and restoration is relatively widespread in
recent prehistoric studies but it concerns mainly fossil Hominids. However,
Paleo-environment and in particular stone tools
carry very important data for knowledge of the cultural evolution through the
changing of lithic technology. We
propose in this paper to study the feasibility of 3D modelling paleolithic tools. Such models are not only useful for archiving purposes but also for
developing new applications as automatic indexing, or automatic refitting, that
are currently studied in the frame of the FOVEA project (Virtual Excavation of
Paleo-Anthropological Environment).
First,
we set-up a state-of-the-art of available 3D acquisition devices. Two casts of
paleolithic tools, one chopper and one chopping tool excavated at Terra Amata,
Nice, France and estimated to around 300,000 years, were selected by a
palaeontology expert. We tested 4 different non-contact 3D acquisition devices
on this set of reference data: stereoscopic cameras, CT-scanner and two 3D laser
scanners (Cyberware and Minolta systems). The resulted 3D models were converted
in a common format and aligned in the same position by an automatic registration
algorithm. It was then possible to compare qualitatively and quantitatively
their resolution and accuracy.
Then,
we tested the possibility to acquire 3D models of lithic tools in-situ, during
the excavation campaign. We
selected a portable non-contact 3D laser scanner (Minolta system) to execute the
3D modeling in a paleolithic excavation: the cave of Arago in Tautavel, France
(450,000 years BC). We
performed 3D acquisitions of three
important elements: first the cleaned artifacts after digging up, second the
casts of the archeo-
stratigraphic
layers in order to replace the artifacts in their archeological context and
third different shoots of a survey sector during a one-day excavation.
JC
Thomas, G Subsol, H de Lumley, V. Poix, B. Mafart, JP Jessel, P Torguet. Workshop
on Archaeology and Computers, Vienna (Austria), 3-4 November 2004.
Prehistory
is a science at the crossroad of many disciplines and requires to compile data
from three main sources : the geology of the site, the environment of the
fossils and the fossils. Then, researchers must handle an enormus quantity of
informations.
In
particular, during the excavation on the prehistoric site of Tautavel (Cave of
Arago, Tautavel, France, 450 000 years BC), archaeologists have found more
than 500 000 objects. The processing of these data is till now performed in 2
dimensions only and their compilation remains difficult. There is then a large
requirement of 3D digital modeling.
The
purpose of our study was to conceive a virtual environment of excavation,
allowing a three-dimensional interaction with the archaeological data. The 3D
environment is composed of the digital copy of the cave in which the objects of
the archaeological database are integrated using the mapping method of Benedikt
space. We have developped tools to make easy the handling of data, the
visualisation and the navigation in the virtual environment : tools of
filtering (focus+context), management of the level of details for the objects,…