Geoscience Reference
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significant difference between 2D map and 2D/3D screen visualization regarding
the performance of some of the visual variables (mainly color and texture).
Secondly, the current tests do not allow us to draw any conclusions about the
specificity of the performance of visual variable when notarial tasks are carried
out. Some of our results nevertheless show that the performance of the visual vari-
able is related to the category of task, depending on the requirement to select or
associate objects. For example, transparency and color (saturation) performed well
with regard to the association of lots into similar groups.
5 Conclusion and Future Works
Based on the hypothesis that 3D cadastral models are helpful for notaries, this
study investigated their appreciation of visual variables for achieving specific tasks
from viewing 3D models. Six visualization tasks for notarial purposes were pre-
sented and 30 visual solutions were tested in changing color (hue and saturation),
value, texture, position, transparency. Compare to previous works, the chapter pre-
sent the suitability of graphic appearance of 3D model from a less technical design
process point of view. It focuses on users, the specialist in a specific field.
The results show that, similar to 2D cartography, color (hue) is one of the
promising solutions for visualisation tasks when selection purpose is required. The
tests reveal that color (hue and saturation) applied to solid perform well, no mat-
ter is the visualization task evaluated. The use of transparency is helpful in some
cases, more specifically when reading annotation (official measures). However,
confusion arises when too extensive geometry of 3D lots is viewed simultaneously
and unnecessary when the geometry of the lots is fully visible. The typical black
and white representation (boundary lines in black and volumes in white) shows
acceptable results in certain tasks, even though it was never the best or the pre-
ferred solution. Moving the position of the geometry of objects, as proposed in
cartographic generalisation principles, seems promising and more investigation
is required. Regardless of these preliminary results, some visual solutions would
require fine-tuning and a larger number of visual solutions would be required,
depending on the task. The 30 visual solutions produced during these first experi-
ments formed, nevertheless, a useful foundation for further analysis.
The approach undertaken is mainly empirical and based on interviews with
notaries involved in co-ownership establishment. This approach helps us to bet-
ter consider the end-user's interests and take into consideration their professional
opinion and requirement. The approach has the advantages of being oriented to
specific visualisation tasks and tested for one domain of application (cadastre).
However, this approach also presents some important limitations such as being
subjective, dependent on the visual solutions tested and the visualization tasks per-
formed, and the fact that it is currently limited to four interviews. The approach
and the results may be rather imprecise since many factors, ranging from factors
of visual solutions to environmental factors may influence appreciation by users.
