CIPA 2003 XIX"' International Symposium, 30 September - 04 October, 2003, Antalya, Turkey
Fig. 3: Processing steps in Geomagic Raindrop Software.
UL: Result of first meshing.
UR: After checking for manifold meshes and cleaning.
LL: Positions of holes. LR: Final result.
Approx. Scale 1:4
that in the end caused the adjacent hole. These holes remain
after the automatic filling. In these cases, the last row of
triangles around the holes is removed and the automatic filling
procedure, when applied again, will be successful for further
holes. If the object structure is very complex, which is not
unusual in the neighborhood of holes, the hole filling has to be
accomplished in an interactive manual process which is very
time-consuming. The hole filling treatment for one single relief
may require up to four working days!
When all holes are removed from the six separate parts, a
complete model of the relief is merged again. As mentioned
above, this ‘Merge Polygon Objects’ process can handle only
about 4 million points. This is the reason why a very high
resolution model cannot be produced for one whole relief. If
any holes are left that extend from one previously separated part
to an other one, this area, including the complete hole, has to be
selected now, the holes have to be filled and the separated area
has to be merged again with the rest of the model.
All points and triangles created in the hole filling process are
also stored in a separate file, since they can be used again when
the very high resolution model is created (see section 4.2).
4.2 Very high resolution model (5 to 6 models per relief)
A point distance of 0.1 mm is aimed at for the very high resolu
tion model. All scanned points as merged for the fine model
(see 4.1, merging) plus all points resulting from the hole filling
process as described in section 4.1 are introduced. Then the
points are thinned to a uniform 0.1 mm point width. In order to
make data handling possible, the relief is now divided into 5 to
6 sub-models which should contain not more than 3 million
points each.
The following procedures are much the same as described
above for the fine model: The points are meshed and cleaned.
Manifold checks are applied after every procedure that results in
data changes. New holes appearing in the model because of the
more sensible meshing parameters must be filled. This has to be
done in subsets which have to be merged again afterwards.
4.3 Coarse resolution model (one model for the cenothaph)
Fig. 4: Coarse resolution model (shaded view of point cloud)
