Geoscience Reference
In-Depth Information
Feature
P
* FeatureID INTEGER
Feature_PK (FeatureID)
Vertex
FeatureComposition
PF * Feature_FeatureID INTEGER
PF * Half-Arc_Half-ArcID INTEGER
FeatureComposition_PK (Feature_FeatureID, Half-Arc_Half-ArcID)
P
* VertexID
INTEGER
Geometric Location
SDO_GEOMETRY
Vertex_PK (VertexID)
Half-Edge
P
* Half-EdgeID
INTEGER
F
* S
INTEGER
F
* D
INTEGER
F
* V
INTEGER
F
* N_V
INTEGER
F
* N_F INTEGER
Half-Edge_PK (Half-EdgeID)
Fig. 8
The relational diagram of the dual half-edge data structure
Feature
P
* FeatureID INTEGER
Feature_PK (FeatureID)
Vertex
P
* VertexID
INTEGER
Geometric Location
SDO_GEOMETRY
FeatureComposition
PF * Feature_FeatureID INTEGER
PF * Half-Arc_Half-ArcID INTEGER
FeatureComposition_PK (Feature_FeatureID, Half-Arc_Half-ArcID)
Vertex_PK (VertexID)
Half-Arc
P
* Half-ArcID
INTEGER
F
* S
INTEGER
F
* D
INTEGER
F
* V
INTEGER
IntermediateEdge
F
* N_V
INTEGER
F
* N_F INTEGER
Half-Arc_PK (Half-ArcID)
P
* IntermediateEdgeID
INTEGER
F
* Half-Arc INTEGER
Geometric Location 1 SDO_GEOMETRY
Geometric Location 2 SDO_GEOMETRY
IntermediateEdge_PK (IntermediateEdgeID)
Fig. 9
The relational diagram of the dual half-arc data structure
geometric object by continuously deforming the primal subdivision of its Dual
Half-Arc data structure to that geometric object. For example, we can model a
cylinder as the glueing of two half-cylinders at their two end straight line seg-
ments. However, we can also consider the cylinder as the deformation of its
development (a rectangle) to bend it continuously until its final shape and then,
glueing the two end straight line segments. Then, we even need fewer Dual Half-
Arcs, as shown in Fig. 12 , which we call the simplified Dual Half-Arc data
 
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