Geoscience Reference
In-Depth Information
Table 2
Analyses of the first question of scenario 1 (comparison between the proposed 3D
metadata and CGDI discovery portal)
Analyses
Question
How 3D shape is accessible in the building dataset?
The proposed 3D metadata
CGDI discovery portal
Explicit?
Ye s
No
Conceptual integrity/limits • Defined as an aspect of
3D context
-
geometric
/
attribute
based / rule based
• Outlined by 3D geometric
structures
• Limited to elevation encoding
-
coordinate/attribute based
• No indication on 3D geometric
structures
Syntactic integrity/limits
•
Context Type
and
Conceptualization
enumerated properties of
Context 3D
class
•
Geometric Content
enumerated
property of
Geometric Data
Structure
class
N/A
Scenario 1: Seeking 3D Datasets for 3D Representation of Building/Urban Energy
Consumption Models
Modern building energy consumption models demand the 3D geometric measures
which are classified according to specific building parts such as rooms, walls, doors,
and windows (Zamyadi et al.
2013
; National Construction Code of Australia
2013
;
National Renewable Energy Laboratory of US
2011
). Strzalka et al. (
2011
) indicate
that urban energy models apply 3D city data at different levels of granularity. While
semantic 3D models are preferred for the finer granularity (individual buildings),
2D footprints with height attribute (i.e. extrusion) are sufficient at rough granularity
(groups of identical buildings or city districts). Accordingly, this scenario simulates
such demands by posing the following questions:
• How 3D shape is accessible in the building dataset? (analyses in Table
2
)
• What is the corresponding LoD of the building dataset? (analyses in Table
3
)
Scenario 2: Seeking 3D Datasets for Consistent Above/Under-Ground 3D
Modeling
This scenario is inspired by the agreement among Quebec's public utility com-
pany (Hydro Québec), Quebec Municipalities Union (Union des municipalités du
Québec), and two major land line providers (Bell Canada and Vidéotron) to inte-
grate cadastral plans with the existing and anticipated underground utility net-
works (Hq-Umq-Bwll-VTron
1996
) . Providing more precise information on the
vertical location and spacing of the underground utilities is one of the highlighted
suggestions of the latest version of this agreement. As indicated by Becker et al.
(
2013
), this requires knowing about the multiple vertical references which may
exist in a dataset or among various CAD and GIS datasets (e.g. known vertical
