66 © 2015 Open Geospatial Consortium
Dec Hex
Char Dec
Hex Char
Dec Hex
Char
46 2E
. 78
4E N
110 6E
n
47 2F
79 4F
O 111
6F o
48 30
80 50
P 112
70 p
49 31
1 81
51 Q
113 71
q
50 32
2 82
52 R
114 72
r
51 33
3 83
53 S
115 73
s
52 34
4 84
54 T
116 74
t
53 35
5 85
55 U
117 75
u
54 36
6 86
56 V
118 76
v
55 37
7 87
57 W
119 77
w
56 38
8 88
58 X
120 78
x
57 39
9 89
59 Y
121 79
y
58 3A
: 90
5A Z
122 7A
z
59 3B
; 91
5B [
123 7B
{
60 3C
92 5C
\ 124
7C |
61 3D
= 93
5D ]
125 7D
}
62 3E
94 5E
126 7E
~
63 3F
? 95
5F _
127 7F
2.2.2 A word about case-sensitiveness
One of the intent guiding the development of the CDB Specification is the possibility of implementing it on modern operating systems whether they are Windows-like or Unix-like.
Throughout this Specification, the reader will notice that file names and directory paths are specified using a mix of upper and lower cases. This choice is made to improve and ease the
readability of those names.
However, it is important to note that no two names are to differ only by their case. After all, a name is used to designate a single object or concept whether that name is spelled in lowercase or
uppercase or even using mixed case. For instance, the terms house, House, and HOUSE and even HoUsE all convey the same idea of a residence where people live. And this stays true for
all combination of cases.
As a result, the CDB Specification demands that all names appear exactly as specified in this document, including the appendices.
67 © 2015 Open Geospatial Consortium
2.3 Light Naming
The CDB Specification provides the means to unambiguously tag any modeled light point
45
with a descriptive name. This provides client-devices with the information necessary to control all
light points that have been tagged with a name that conforms to this Specification. The CDB Specification provides a comprehensive set of light types, particularly well suited to
the needs of Visual simulation. Light types include those found on: cultural features including point, lineals, areals, and specialized airport
systems air, land, and surface platforms
life forms munitions
Each light type defined by this Specification, corresponds to a real-world light type. The Specification provides a definition of each light type, which is representative of the light type’s
function rather that its characteristics. The client-devices use the light type name as an index to derive the properties and characteristics of the light. The approach is client-device independent
because the device-specific client rendering parameters are not stored in the CDB and are therefore invisible to the modeler and the database tools. The modelertools need not be
concerned with dozens of parameters that describe the light’s properties and characteristics. The client-devices internally build and initialize a table of light properties and characteristics for their
respective use. The table is nominally built at CDB load time and is built to match the device’s inherent capabilities and level-of-fidelity.
The light point types are structured in a hierarchy that is designed to simplify the modeler’s workload. Increasing levels of specialization are possible if a modeler specifies light names
located in deeper levels of the light naming hierarchy, i.e., the more specialized the light, the deeper the level.
An extract from the light naming hierarchy is illustrated in Figure 2-5: Extract from Light Naming Hierarchy as an example. This portion of the light naming hierarchy concerns itself
with lights used for “Line-based Cultural” light points e.g., streets, highways. Immediately below the “Line-Based” level, the modeler can choose from a wide selection of lights such as
Fluorescent_Light, Incandescent_Light, or Sodium_Light. A modeler that does not want to concern itself with the particular characteristics of highway lights may choose to tag its lights
with a name that is higher up in CDB light name hierarchy. On the other hand, a modeler that has more elaborate source data and has more time at his disposal may choose to differentiate
between “Multilane_Divided_Hwy” and “Highway” andor “Sodium” and “Incandescent” lighting further down in the CDB light name hierarchy.
45
The CDB Specification does not distinguish between a light-point and a light-source. In the simulation industry, the term light-point refers to a point source of light that does not illuminate its immediate surroundings. Likewise,
the term light-source refers to a point source of light capable of illuminating its immediate surroundings.
68 © 2015 Open Geospatial Consortium
Figure 2-5: Extract from Light Naming Hierarchy
