Geoscience Reference
In-Depth Information
3D viewing, several questions still require fine-tuning, such as whether or not 2D
mapping rules fully apply to 3D, do standards for good practices to symbolize 3D
models exist, do other specificities relate to 3D model visualization such as usages
or the profile of users exist. For example, Pegg (
2009
) concluded that viewing
angles and illumination are prominent factors in 3D models compared to visual
variables. Hardisty (
2001
) suggested reflectance was another visual variable in
the theoretical investigation of 3D visualization and recognized that light sources,
cameras and even fog are persuasive visual properties.
Literature is rich about the advantages of using 3D cadastral models (Aien et
al.
2011
; Ekbäck
2011
; Erba
2012
; Pouliot et al.
2010
; Stoter
2004
). Assuming
that 3D cadastral models of a condominium may optimize decision making for
notarial purposes, this study will assess some visual variables and visual enhance-
ment techniques to support this process. The study will address this question by
estimating whether or not some of the visual variables (color hue and saturation,
value, texture) and visual enhancement techniques (adding and moving elements,
transparency) perform better for notarial decision making within the context of
co-ownership establishment. Six notarial tasks or decision-making scenarios were
predefined for testing purposes. Assessing 3D visual solutions is done through
interviews with civil law notaries; the users targeted for these first experiments.
During the interviews, the notaries were asked a series of questions, based on the
visualization of various 3D geometric models of the condominium on a computer
screen. No interaction with the 3D geometric model was allowed in this first exper-
iment, since the focus is only on 3D visualization. This empirical approach appears
to be beneficial to gain a better understanding and integrate the end-users' point of
view, not that of the 3D model's designer. The chapter presents the suitability of
graphic quality of 3D model from a less technical point of view than several other
publications. It focuses on users (notaries), specialists in a specific field. Moreover,
this profession does not currently use 3D models, so the conclusions may help pro-
moting the application of 3D models for cadastral purposes. The interview-based
strategy also has limits, which will be discussed later. In some ways, this approach
appears unique in cadastral applications compared to other methods observed in the
literature and few analyses of visual variables and 3D model integrate professional
tasks or users in the assessment. To complete this analysis and provide some verifi-
cation of preliminary results, a comparison with three significant references in the
literature referring to the semiology of graphics (Bertin, Carpendale and Ware) is
proposed. The comparison takes into consideration the selective characteristic (the
ability to make choices) of the visual variable to enable the comparison.
This study is a follow-up to the preliminary tests conducted in 2012 with theo-
retical users, tasks and 3D models (Wang et al.
2012
). In the present research, a
real case of a complex building is used, with three notaries who are currently per-
forming notarial tasks regarding the condominium (e.g. delimitation of property
right). The notaries are acting within the context of Quebec civil law. The ulti-
mate purpose of these research activities is to guide the establishment of 3D car-
tographic design aspects and to promote good practices in 3D modelling activities
applied to non-conventional domains.
