The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B4. Beijing 2008
344
Figure 1 Primitives of 00-Solid Model Component
(1) Node.
The node is classified into six basis types, such as cru-node,
inner-node, isolated-node, reference-node, interpolated-node,
and feature-node.
It can be divided into three classes from geometric feature: A.
u-node is the start and end node of the arc. B. Inner-node is the
node except cru-node. C. Isolated node is the node not in the arc,
which is on the surface or in the inner of component.
It can be divided into two classes from the data source and
reliability: D. Reference-node is in the boundary arc of
component and can’t be arbitrarily changed. These nodes are the
first-hand information obtained from exploration or mine
production. E. Interpolated-node is the interpolation node in
order to improve the geometric modeling or attributes modeling
accuracy.
In order to increase the degree of automation modeling
deliberately set the node type is feature-node, which is the
common node of arcs with different attributes. 3DGMIS can
automatically connect the feature-nodes of the same attributes in
the three component polygons, and form feature-line.
(2) Arc
The arc, defined by cru-node(start-node and end-node) and a
number of inner-nodes, is the border of polygon. Feature-line is
abstracted as arc, but it have a special meaning or
significance-bound meaning, and can be automatically connect
by system or connect interactive by users.
(3) Polygon
It is outer border or inner borders of a region, and have direction
(counterclockwise as positive, negative for the
clockwise).Polygon composed by arcs. 4
(4) Region
The common face between component and another component
or between component and surface object (such as fault plane)
is abstracted as region. And it often is a part of component-face.
Region, having a certain attributes, is composed by one
outer-polygon, n(n ^ 0) inner-polygon, and m(m ^ 0)
isolated-nodes. As an independent object, region can be
modeled into one only regional with using modeling algorithm
(such as generating a DTM with polygons and isolated-nodes
using certain algorithm). This will help to reduce duplication of
constructing common face, but also to avoid singular problem
of common face. During dynamic updating of geological model,
automatically updating of component-face, component, surface
object or volume object can be realized with only updating
region. Which will reduce the necessary resources of the
dynamic maintenance, for example, when adding a
reference-node to a component face, only the region including
this node need to updating, then component face, component,
surface object and volume object can be automatically updating.
(5) Component face
Component further classified into component-side-face,
component-up-down-face, component-polygon-face. The
sections in the OO-Solid model have generalized meaning,
which isn’t confined to geological section; it could be level, tilt
or arbitrary surface of the two-dimensional space.
Component-polygon-face can be composed of a number of
polygons or can degenerate into a line or a node. The
classification of component-side-face with component-up-
down-face is conducive to seamlessly integrate with facet
model.
(6) Component
Component can be defined by fore-component-polygon,
mid-component- polygon and post-component-polygon and
which surface can be represented by component faces.
3.2 Superiority for modification of primitives
The revised OO-Solid Model component in this paper is
different from the model component put forth by writer (2002)
in the following aspects:
(1) In dynamic modeling or updating, it is very important to
define node from three different angles. Dividing the node into
Cru-Node, Inner-Node, and Isolated Node from the geometric
angle will help form the topological relationship of polygon
automatically, and dynamically update node data change in
dynamic updating in geological modeling. Dividing the node
into Reference Node, Interpolated Node from the aspect of data
source and reliability will be beneficial to the topological
consistency analysis and dynamic updating of node data. The
division of feature node is to dynamically form feature joining
line, which will help distinguish region of different features and
then distinguish line object, face object, body object.
(2) The connotation of feature joining line changed from the
original definition “the line segment joining the feature nodes
on section border” to “the arc joining the feature nodes on
section border”. The revised definition has even wider meanings,
including not only the inferred information given by users
mutually and binding line, but the dividing arc of Component
Up-Down Face and Component Side-Face, in order to express
the face object in a more convenient way.
(3) The addition of two model components: polygon and region;
polygon is the inner or outside border of region, and region not
only decides the inner and outside border, but take Isolated
Node into consideration. The definition of region ensures that
section polygon can show the relationship of embodiment of
polygon and even express the relationship of embodiment of
geological object. Meanwhile, region is a part of component
face and the modeling of region is isolated from data structure.
Therefore, region is not only the member of neighboring
components, but also a part of a face object, which will help the
component further form body object and face object.
(4) The component face was further divided into Component
Polygon Face, Component Up-Down Face, and Component
Side-Face, which will help integrate the different faces of
component, form model of their own and show the object of
different faces separately. For example, Component Side-Face
can be seen as fault surface, Up-Down Face can be seen as
upper plate or bottom plate of ore body. Through the features of
region and their topological relationships, the component
