There are five types of objects in GoPhast. These are:
Each object consists of one or more vertices and has properties associated with it. The properties of an object determine how it is used to specify spatial properties of the model. Each object is associated with one of the three views of the model (top, front, or side).
Objects are created by drawing them on the top, front or side views of the model. The following sections describe how to create each type of object.
Point objects have only a single vertex. To create a point
object, the user does the following. (1) The user either selects Object|Create
Point or clicks on the point button. (2) The user
moves the cursor to the location on one of the views of the model where
a point object is desired. (3) The user clicks the mouse
button. A point object will be created at the cursor
location. The Object Properties
dialog box (See p. 48) will
appear. The Object Properties dialog box is used to specify the
properties of the object.
Typical uses for point objects would be to define the elevations of the tops or bottoms of geologic units, point values for hydraulic properties that will be defined using interpolation, or well boundary conditions.
Polyline objects have two or more vertices. To create a
polyline object, the user does the following. (1) The user either
selects Object|Create Line or clicks on the polyline
button. (2) The user moves the cursor to
the location on one of the views of the model where the first vertex of
the polyline object is desired. (3) The user clicks the mouse
button. The first vertex of the polyline object will be created
at the cursor location. (4) To create additional vertices, the
user continues clicking on the same view of the model. (5) When
all the desired vertices have been created, the user double-clicks at
the last vertex or depresses the “Enter” key on the keyboard to
complete the polyline. As with points, the Object Properties
dialog box (See p. 48) will be
used to specify the properties of the
object.
Typical uses for polylines are to define linear features such as rivers and boundary conditions located at the edge of the model.
Polygon objects have four or more vertices. The last vertex is
always at the same location as the first vertex so a polygon with four
vertices is a triangle. To create a polygon object, the user does
the following. (1) The user either selects Object|Create
Polygon or clicks on the polygon button. (2) The
user continues adding vertices as described with Polylines. (3)
When the polygon is complete, a final vertex will be added at the
location of the first vertex to close the polygon. As with
points, the Object Properties dialog
box (See p. 48) will be used
to
specify the properties of the object.
Typical uses for polygons are to define zones with differing media properties.
Straight-line objects are a special case of polylines in which all
the line segments in the polyline are parallel with one of the edges of
the grid. To create a Straight-line object, the user does the
following. (1) The user either selects Object|Create Straight
Line or clicks on the Straight-line button. (2)
The user continues adding vertices as described with Polylines.
As with points, the Object Properties
dialog box (See p. 48) will be
used to specify the properties of the object.
Typical uses of straight-line objects are the same as for polylines.
Rectangles are a special case of polygons that have four edges that
are parallel to the grid. To create a rectangle, the user does
the following. (1) The user either selects Object|Create
Rectangle or clicks on the rectangle button. (2) The
user moves the cursor to the location on one of the views of the model
where the first vertex of the rectangle object is desired. (3)
The user clicks the mouse button again at the opposite corner of the
rectangle. As with points, the Object
Properties dialog box (See p. 48)
will be used to specify the properties of the object.
Typical uses of rectangle objects are the same as for polygons.
To edit, move, or delete and object, the object must first be selected. Selected objects can be distinguished from objects that are not selected because the line used to draw the selected object is thicker and the vertices of the selected object are drawn as squares. However, point objects are also drawn as squares even if they are not selected. Selected point objects are drawn as solid squares whereas point objects that are not selected are drawn as hollow squares. The object in figure 21A is selected; the object in figure 21B is not. The object in figure 21C has one of its vertices selected.
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A |
B |
C |
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Figure 21. Appearance of (A) selected object (B) non-selected object and (C) an object with a selected vertex. |
There are several ways to select objects. The easiest is to
click on the Select objects button and then click on
the object. Another way is instead of clicking on an object,
click down somewhere on one view of the model that is not on any object
and then drag the mouse button. A rectangle will be drawn
starting where the mouse was clicked down. When the mouse button
is released, any objects that are entirely within the rectangle will be
selected. Another option is to click on the Lasso
button
.
Then the user clicks down on one view of the model and moves the
mouse. A line will follow the mouse. When the user releases
the mouse, any objects that are entirely within the line will be
selected.
Usually, selecting one object causes any object that was already selected to be deselected. However, if the Shift key is held down while selecting an object, then the objects that would normally be selected are toggled between selected and deselected and other objects remain selected.
The Ctrl key also modifies how selection occurs when the Select
objects button is down but not when the Lasso
button is
down. The user can use the Ctrl key to select objects beneath
another object. If several objects are on top of one another, the
user can click on the objects with the Ctrl key down and if none of the
objects is selected, the uppermost one will be selected. If the
user clicks again with the Ctrl key down, the top object will be
deselected and the next one down will be selected. If the user
clicks again with the Ctrl key down, the object below that will be
selected. The Shift and Ctrl key can be combined.
Individual vertices of an object can be selected as well as whole
objects. To select individual vertices, the user first selects an
object and then clicks on the Select vertices button .
Next, the user clicks on the vertex he or she wishes to select.
To select additional vertices, the user clicks on them while holding
down the Shift key. Vertices can only be selected on objects that are
selected. The user can also click down away from any vertices of
a selected object, drag the mouse and release it to select vertices
that are inside the rectangle defined by the locations where the user
clicked down with the mouse button and where the user released
it. All the vertices outside the rectangle will be deselected
(unless the Shift key is down). If the user holds down the Shift
key while clicking on a vertex, it will be toggled from selected to
deselected or the reverse.
A number of dialog boxes allow the user to select objects. See “Search for Objects Dialog Box” on p. 56, “Show or Hide Objects Dialog Box” on p. 56, “Select Objects by Name Dialog Box” on p. 58, and “Changing the Magnification” on p. 59.
There are a number of ways to edit objects. Objects can be deleted or moved. Individual vertices in objects can be inserted, moved or deleted. Edges of objects can be deleted. The order of the objects can be changed. Finally, the properties of objects can be changed.
To delete an object, select it and press the delete key on the keyboard. To delete individual vertices, select the vertices and press the delete key. One way to move objects or vertices is to select them, hold down the mouse button with the mouse curser on or inside the object, and move the mouse before releasing the mouse button. Another way to move an object or individual vertices is to double click on the object. Then on the tab labeled Vertices, type in new values for the coordinates of the vertices.
To insert a vertex, first click on the Insert vertex
button . Then click on the edge of
an object to insert a vertex at the position where the mouse was
clicked. If any object is selected, this procedure will only
insert a vertex in the selected object. If no object is selected,
this procedure will insert a vertex into whichever object on which the
user clicks. To delete an edge of an object, click on the Delete
segment button
. Then click on an edge of an
object to delete that edge. If deleting an edge will split the
object into two separate pieces, one of the pieces will be a new object
with the same properties as the original object except for its name.
To change the order of objects, select one or more objects and right click on them. Select one of the options in the pop-up menu to change the order of the objects. It is also possible to select Object|Rearrange Objects… The Rearrange Objects dialog box (p. 48) will appear. In it, the user can drag objects to new positions.
To edit the properties of one or more objects, select them and then double-click on one of them. The Object Properties dialog box (p. 48) will appear in which the properties can be edited. The user can also display the Object Properties dialog box to edit the properties of a single object by displaying the “Show or Hide Objects Dialog Box” (p. 56) and double-clicking on the name of the object.