- 100 -
3.4 Consolidation of cloud points
Consolidation of the cloud of points obtained by the laser scan
from different viewpoints is also relatively immediate (provided
the sphere targets are used). A cloud of points model rendered
the temple immediately identifiable. Once consolidated how
ever, an interesting issue arose at the meshing stage. The addi
tional points produced at the juncture where scans overlap need
to be removed through the spatial filtering command 13 other
wise homogeneity will not be obtained. Indeed, if a 2mm grid
resolution is required, then such a grid has to be chosen at the
outset.
practical issues prohibit satisfactory coverage. This occurs when
‘Automatic Computation of a mesh’ is used to triangulate a
complete cloud of points. However, this method is only really
effective when the cloud of points is sufficiently dense and ho
mogenous (See Fig. 8). In the meshing triangulation by projec
tion method, no holes are created because all the available
points are computed in the mesh. This seems to result in an
advantage However if a hole exists in reality, it will be filled up
also. It often occurs that it is very difficult to decipher the filled
holes from those holes which exist in reality.
3.6 Problems with texture mapping
3.5 (At least) Two ways of meshing laser scan data.
The 3D Ipsos software has two methods of meshing available to
the user: automatic or by projection. The use of a mesh to sur
face the scan data may result in small holes where data has not
been captured, for example where reflectance is low or where
When it came to texture mapping, certain problems were evi
dent. The integrated camera of the Mensi Soisic LG scanner has
a relatively low resolution since its primary function at design
stage was evidently merely that of an aiming device as opposed
to a recording mechanism. The SOISIC LG scanner has to be
used in low light, almost darkness, while the camera requires
Fig. 7 Overlapping of points from different scans produces relief to right of tomb
13 available in both the 3DIPSOS and DIAP TIN software