Using Graphics
You can view, modify, and query string and DTM data in Graphics.
Layers
GRAPHICS has the ability to recall files into a layer which is identified by a user specified name. This provides a facility similar to transparent overlays when doing drafting. The data from various layers can be seen together but only the data on the top layer - the active layer can be changed. The active layer can be changed and data can be copied from any layer into the active layer.
Multiple viewports
It is possible to view more than one set of data at once and also to display the same data rendered in different ways or from different viewing positions by making use of multiple viewports. Initially GRAPHICS starts with a single viewport but by using buttons on the viewport title bar it is possible to make copies of the current viewport.
To create multiple viewports you right click in Graphics and select either Split vertically or Split horizontally. The viewport you right clicked in will be divided in two.
When the same layer is visible in two separate viewports it is drawn the same, that is with the same colours and styles, however the viewing parameters (viewing position, viewing type, face visibility, etc) can be different between the two viewports. To view the same data with different drawing parameters (e.g. some strings drawn as markers in one viewport but polylines in the other) you simply need to load the same file into two different layers and make the appropriate layer visible in the appropriate viewport.
When more than one viewport is displayed only one will be considered the active viewport and it is that viewport which needs to be used for selecting or digitising points. It is not possible to select points in non-active viewports. To change a viewport to be the active viewport simply use the mouse to click in the viewport, or on the viewport title bar. A highlighted menu bar indicates the currently active viewport.
All interactions with the viewports are achieved via the viewport icons along the title bar at the top of the screen. The effects of these icons are:
- Solid diamond - creates a copy of the viewport with the same layers and settings.
- Solid downward triangle - splits the viewport in half horizontally.
- Solid rightward triangle - splits the viewport in half vertically.
- Open downward triangle - close the viewport to an icon.
- Open square - Maximise the viewport (that is, make it take up the whole region for viewports), or if it is already maximised return the viewport to its previous size and position.
- Crossed square - destroy the viewport. If only one viewport remains then it cannot be destroyed.
Dragging the title bar allows you to move viewports and a resize icon in each corner allows the viewport to be resized. The view bar along the bottom of the viewport area works in a similar to the task bar in Windows 95 and allows a quick means of selecting the active view or opening a closed viewport.
Whenever the "Function:" prompt is displayed it is possible to modify how the scene in any viewport is seen by using the mouse. This provides a simple means to rotate (left mouse button), roll (right mouse button), or dolly (middle mouse button, or left and right mouse buttons together on two button mice) by simply clicking and dragging the mouse in the viewport.
Point and Drag or Click and Drag
Some of the functions in GRAPHICS will display a prompt which reads something like, ``Point and drag ... (perform some action)''.
``Point'' means move the mouse to place the pointer over an item.
The ``action performed'' will relate to the function being used.
'drag'' means hold down the mouse button as you move the pointer:
- depress a button on the mouse
- without releasing the button move the mouse to a new position
- when at the required position release the button on the mouse.
Graphical feed back will be displayed to help you see the result of your actions.
Point Selection
GRAPHICS uses a sophisticated method for determining which point is selected when performing graphical selection operations. The selection method is based on the following:
- proximity to the piece of geometry, and
- proximity to the point within the selected geometry.
The term geometry in this context refers to something which has been drawn on the screen and is selectable, this includes:
- lines
- polygons
- triangles
- markers
- Collar and end of hole locations of drillholes that have been drawn from a geology database.
- Survey stations that have been drawn from a survey database. The lines that can be drawn between survey stations are not selectable.
Whether a function will permit stations or drillholes to be selected is dependent on the requirements of the function. Some functions, SEGMENT DELETE for example, only operate on points, segments and strings. For these functions the selections are restricted to points, segments and strings. Other functions have greater flexibility and permit selections on stations and drillholes, subject to selectability settings that can be altered for these data types. Examples of functions that permit selections on drillholes, stations and points are Identify Point, Bearing and Distance, Circle, to name a few. A general guide to help you understand which functions do not permit selections on drillholes and stations is that if a function is going to modify a point, segment or string in some way then the selection will be restricted to points, segments or strings.
The selection method for lines, polygons and markers means that you unambiguously select a point on a particular line by positioning the pointer near to the line and in such a position that it is closer to the point of interest on that line than any other point on that line. This is particularly useful when two or more lines have points with the same X, Y and Z values.
Mouse button behaviour for digitise actions
You use the left mouse button for all digitising actions. You use the snap modes to digitise at different locations in Graphics. The middle and right mouse buttons, and the scrolling wheel, perform their usual viewing functions. That is, the right button displays the snap mode context menu, and the middle button pans or zooms.
Special event handling during point select, point digitise and triangle select operations.
During these operations the system will respond to two special types of events which often prove quite useful during graphics editing or design work. These are:
- ASSIST events. The ASSIST event is generated by pressing the ASSIST button, generally F11, to invoke the Viewer. This is very useful as it permits you to modify the view by windowing in or out or by rotating the view to suit your needs. On exiting from the Viewer, the point select, point digitise or triangle select operation is still active.
- Viewport Manager events. Each Viewport has a number of active icons to permit the viewport to be modified in some way. The move and resize icons on the viewport which is active at the time of the point select, point digitise or triangle select operation may be used to move or resize the active viewport. This is useful if the viewport is too small or if the viewport is partially obscured. If another viewport is selected then the point selection operation is cancelled.
Point Modes
Many of the GRAPHICS functions have three possible results determined by the current point mode.
The point may be one of:
| MODE Add | New points are added to the end of the last segment of the DESIGN String. The DESIGN String is the current string being used in the design process. MODE Add is the default mode. |
| MODE Change | The selected point or segment is changed to a new location. |
| MODE Insert | The new point or segment is inserted into the selected string at the point indicated by the user. |
The point mode is selected by choosing Add point mode, Change point mode or Insert point mode from the toolbar, or by right-clicking in Graphics and choosing the mode. The point mode remains the current point mode until another point mode is selected. The default mode is Add.
Undo
Surpac uses an efficient storage structure to minimise the amount of memory used for storing previous versions of the graphics layer. Only a small amount of extra memory will be used when the operation makes minor changes to a layer, for example, retaining undo information about deleting a point does not use much memory since the before and after versions are almost identical. However, substantial memory may be used if the layer is changed completely, for example, undo information for recalling a file requires memory to store the previous version as well as the current version since no part of the layer is shared between the before and after versions.
To prevent excessive memory being used for previous versions the number of undo versions, i.e. the number of operations for which undo information can be kept at a time is limited and is set by the user default "maximum undo operations" (in the defaults.ssi file) or can be modified by Undo Setup. To further reduce memory when using Recall File, all undo information except for the immediately preceeding version, is destroyed. The user default ``clear undo on recall file'' may be set to ``off'' to ensure that edit operations before the recall file operation can be undone.
Undo functionality can be turned on or off using Undo Off or Undo On. The undo parameters can be modified via Undo Setup and the current undo history can be purged using Undo Clear.
Note: Operations on layers
which contain DTMs or 3DMs cannot be undone with the current release of
the software. This limitation is likely to be removed in a future release.
Note: When operations are
undone or redone sometimes strings, segments, or points will not be redrawn
in exactly the same manner as in the original version. This is particularly
noticeable when a deleted entity is redrawn when the delete is undone.
Reset graphics
You can clear all of the data from the graphics viewport by clicking Reset graphics
. When you reset graphics, the data from the viewing area and the data from the layer manager is cleared. Surpac resets the active plane and switches back to 3D plane mode, which erases the dynamic grid or 3D work area if they were displayed.
To run this function: Choose File > Reset Graphics, or...