Encom Discover 3D Complete Training Workshop

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ENCOM DISCOVER

3D

COMPLETE TRAINING

(WORKSHOP)

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Table of Contents i

1 Introduction

Encom Discover 3D is a separate add-on module designed to work seamlessly with Encom Discover. The module is automatically disabled in the Discover menu unless the Discover 3D module has been purchased.

Surfaces representing topography, geochemistry and geophysics, drillhole sections containing assays or lithological data or any other mapped data combinations created using MapInfo/Discover can be transferred to the Discover 3D interactive three-dimensional environment. Additional objects such as 3D DXFs, grid surfaces and raster images plus point and line data can be added to the 3D displays from MapInfo or independently.

Discover 3D enables data to be viewed interactively with zooming, panning and fly-through capability. View orientations can also be taken from Discover 3D back into MapInfo and displayed in a layout for presentation purposes.

Discover 3D operates seamlessly with Encom Discover. If you know how to create a map, a drillhole project and sections in Discover, this is all you need to operate Discover 3D. No additional project specification or data setup is required since the displays within MapInfo, created by Discover, are passed directly to Discover 3D for presentation and interactive use.

The Discover 3D display below is typical of the type of displays derived from various data types.

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Discover 3D Data Formats 3

2 Discover 3D Data Formats

The Discover 3D module comprises both a Discover 3D menu within the 2D/MapInfo interface, as well as its own separate 3D interface/window. These allow a 3D display to be created both from datasets already open within 2D MapInfo/Discover interface, and/or by opening applicable data directly into the 3D window. This allows a large range of data formats to be created and supported by Discover 3D.

Images

The content of any map window open within MapInfo/Discover can be displayed within the 3D environment as a geo-located image, using the View Map in 3D menu option. This produces a .PNG image with an accompanying .EGB file (georeferencing header file). All data sets visible in the map window (e.g. grids, images, vector data) will be incorporated into the image. The image’s RL can be assigned manually, or it can be ‘draped’ over a gridded surface (e.g. a DEM grid). Drillhole sections and Drillhole Logs can also be displayed as images using the View Sections and View Logs options.

Images can also be directly opened and georeferenced in the 3D window, using the Georeferenced Image Creation Wizard. This wizard supports .BMP, .PNG, .TIF, .GIF and .JPG image formats. Images with an existing .EGB file can also be opened directly from within the 3D window.

A lot of data can be easily displayed in 3D as an image, but the data cannot be modified or interrogated.

DXF/Vector Objects

MapInfo vector data such as points, lines and polygons can be displayed in Discover 3D as DXF files. The View Objects in 3D menu option allows any vector dataset open in MapInfo to be converted into a DXF file and placed into the 3D environment. This could include infrastructure (roads), contour lines (created from a gridded surface using the Surfaces>Contour a Grid menu option) or orebody boundaries interpreted on drillhole cross sections (display in 3D using the View Section Boundary option).

Existing DXF files (eg the output from modelling programs) can be opened directly into Discover 3D via a number of menu options, or by simply dragging and

dropping the DXF from Windows Explorer.

DXF’s are a very efficient way of displaying a large amount of vector data, particularly points and polylines; however they have limited display options.

Points/Lines

Point data in MapInfo tables can be displayed in Discover 3D as 3D Lines or 3D Points. These display types directly reference the source MapInfo TAB file, and providing powerful display controls. These include point labelling, colour, size and rotation modulation by data values, offset controls and support for True Type fonts. Examples of these display formats:

• Colour modulating regional geochemical point datasets

• Displaying prospect scale geochemical data as lines offset by an assay

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4 Encom Discover 3D Workshop Manual

• Displaying flight lines coloured by date.

Displaying data in 3D as Points or Lines therefore gives the user a great deal of display control and options; however instigating these options on large datasets can severely affect 3D rendering performance.

Gridded Surfaces

Grids created using either the Discover>Surfaces menu or other products (eg topographic or geochemical surfaces in formats such as Geosoft, ER Mapper, Surfer etc.) can displayed in Discover 3D either directly or via the View Surface in 3D menu option. A large range of grid types are supported. Support is also provided for the draping of ER Mapper ECW and .ALG files.

Drillholes

Drillholes present in an open Discover Drillhole Project can be displayed in Discover 3D using the View Drillholes menu option. Alternatively, the relevant collar, survey and downhole data .TAB files can be opened directly into Discover 3D if they are assigned to a Discover Drillhole Project. The display of 3D drillholes can be modified by colour and thickness modulation, as well as labelling and annotation options.

Images of cross-sections and drillhole logs created in Discover can also be displayed in 3D. Interpretative linework digitized into cross-sections can be exported into 3D as DXF objects.

Discover 3D can also directly open Geosoft drillhole databases (usually with a suffix .GDB).

Drillhole Selections

A selection from a drillhole project (eg all downhole intervals with Au>50ppb in a subset of drillholes) can be displayed as a DXF file in Discover 3D.

Voxel Models

Discover 3D can create, display and manipulate Voxel block models (eg IP resistivity), supporting formats such as UBC, CEMI, and Noddy, as well as preliminary support for Datamine, Surpac, Vulcan and Gocad Voxet.

Feature Database

Points, polylines and polygons can be digitized and attributed directly into the 3D environment as part of a Feature Database. Additionally, dxf vector or MapInfo TAB files can be imported as feature database objects, and then edited from within the 3D environment. This allows the geoscientist to create interpretations in the 3D environment using all relevant datasets (eg drillholes, geochemical and/or

geophysical grids, voxel models, etc) without the being limited to traditional 2D cross-sections.

3D Symbols

Point data in MapInfo .TAB or .MIF format can be directly displayed in Discover 3D as individually sized and orientated 3D Symbols.

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Discover 3D Data Formats 5

Movies and Fly-Throughs

The Fly-Though Wizard allows the creation of both Encom .FLY files for reuse within the 3D environment, as well as .AVI movie files.

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Discover 3D Menu in the 2D Environment 7

3 Discover 3D Menu in the 2D Environment

To open the Discover 3D menu in the 2D MapInfo/Discover interface select

Discover>Discover 3D. This will place a Discover 3D option on the MapInfo

Professional menu bar.

Discover 3D Menu Options

The Discover 3D menu allows a range of data types open within the

MapInfo/Discover environment to be displayed in the 3D environment. It contains the following functionality:

• Open 3D Window - Open Discover 3D program from MapInfo/Discover

• Open/Save 3D Workspace - Open or save 3D Workspace. A 3D workspace

saves the current MapInfo and Discover 3D session into a single workspace file.

• Refresh All 3D Data – Update data in MapInfo/Discover and send changes

through to Discover 3D without having to close down.

• View Map in 3D – Display a MapInfo map window view as a georeferenced 3D bitmap image.

• View Objects in 3D – Select vector objects from a MapInfo map window

and view as 3D DXF vector file.

• View Surface in 3D – Display a gridded surface open in MapInfo in Discover 3D.

• Create 3D Points - Display geochemical/geophysical data as 3D points.

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• View Drillholes - Display drillholes in 3D. This option loads the entire

drillhole dataset.

• View Sections - Display drillhole sections as georeferenced 3D bitmap images.

• View Logs - Display drillhole logs as georeferenced 3D bitmap images.

• View Section Boundary – Display section orebody or lithological

boundaries as 3D DXF vector files.

• View Drillhole Selection - Display only selected drillholes in 3D. This option

does not load the entire drillhole dataset.

• 3D Display Wizard – Display an entire map window view or objects from a

table through an easy-to-use wizard interface.

• 3D Extrusion Wizard - Extrude 2D bodies in 3D to aid in visualisation of

fault planes, veins or mine infrastructure.

• 3D Utilities – Use the Multi Section Generator to register multiple images

as sections using a series of lines or points. Use the Overlay Image on Grid to drape a raster image over a gridded surface using the original raster resolution.

• Toggle Auto 3D Selection - Turn the Auto 3D selection option On or Off.

• Options – Various user-defined system and display settings to customise Discover 3D such as temporary directory location, surface display and compression options, XYZ indicator, map projection, images resolution, etc.

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Discover 3D Interface 9

4 Discover 3D Interface

The main screen items of Discover 3D

To open the Discover 3D window, select the Discover 3D>Open 3D Window menu option from the Discover 3D menu in the 2D MapInfo interface. The 3D window will open after a short time.

Alternatively, the Discover 3D window can be accessed when a mappable MapInfo tab file is open in MapInfo/Discover by using the appropriate View option from the Discover 3D menu or by right clicking on a displayed MapInfo Professional map and selecting View in 3D…

The 3D Interface

The 3D window is divided into six areas:

• The Main Menu items contain the operational pull-down menu controls.

• A range of buttons within dockable Toolbars are available for controlling

various functions (e.g. navigation, inserting objects etc.). Some of these become active only when certain operations or data events are undertaken. • A Display Window area that initially contains a white background. This area

is used to display windows and dialogs.

• A Status Bar at the base of the screen to indicate processing and display

events, the 3D Navigation Cursor or 3D Cursor coordinates, progress bar and other useful progress information.

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The Workspace Tree on the left of the display window may appear as a separate window or it can be placed or docked where convenient. This tree provides a hierarchy view of all objects, data sources and controls of the various displays. Workspace Tree contents alter when a dataset is accessed or a window is highlighted. The Workspace Tree can be removed from view and restored using the button shown left. It can be re-docked by double clicking on the title bar. The Interactive Help (called iHelp) may appear as a separate window or it can be placed or docked where convenient. This sheet provides online assistance for whatever display option is being used. The Interactive Help can be removed from view and restored using the button shown left. It can be re-docked by double clicking on the title bar.

Navigating in 3D

Discover 3D has two modes for controlling for navigation and specifying view positions and movement, available through the following buttons:

Exercise 4.1 Manoeuvre within the 3D environment.

Data Location: Encom Training\Training 3D\Structure

1. From within Windows File Explorer, navigate to the above directory, and

drag and drop the Interp_Structures_all_3D_iso.dxf into the 3D window.

2. Experiment with the controls as detailed below.

The Navigate button is used generally to make windows active, control the 3D Cursor plane crosshairs, select and edit objects and list items. This option is set by default for normal viewing and display modes (refer to View Modes).

Control of the 3D view is based on the cursor location. It allows the 3D display to spin around a horizontal axis if the cursor is moved vertically (with the left mouse button depressed) or in a circular movement around an axis into the screen when the cursor is moved horizontally.

The 3D Navigation button is used to provide greater control of 3D display manipulation. Sensitivity and speed of movement is controlled by the cursor’s distance from the centre point of the 3D window (the ‘view point’).

After clicking the 3D Navigation button move the cursor to the 3D display window (or click the right button while the cursor is located in the display and select

Navigate 3D). The 3D cursor control sequences are:

• Left mouse button depressed with vertical movement rotates the image

about a horizontal axis running through the view point.

• Left mouse button depressed with horizontal movement rotates the image

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• Right mouse button with vertical movement zooms the image in or out of

the display. The numeric keys (1-0) can be used to control the zoom speed, with 1 & 2 applying the slowest zoom speeds and 9 & 0 the fastest.

• Left and Right buttons depressed with cursor movement allows positioning

of the view point in the X/Y plane. Moving the cursor horizontally pans the view (moving the view point left/right), whilst moving the cursor vertically moves the view point in a ‘fly-through’ operation.

• Keyboard entries with mouse manipulation can also be used to control 3D

display operation. Available combinations include:

• SHIFT key plus pressed left mouse button repositions the view point in the

vertical axis and screen plane (this only operates in Navigate 3D mode). Holding the cursor near the view point reduces the speed of panning.

• CTRL key plus pressed left mouse button repositions/rotates the image view

whilst maintaining the current eye position. Nearer the centre of the view reduces the speed of panning.

Reset 3D View restores the 3D display to a default such that the first displayed

object is centred and shown within the window.

The Page Layout buttons are designed for use mainly within the Page Layout view. The Zoom In and Zoom Out controls allow adjustment of the overall zoom ratio of the page display, whilst the Pan button enables you to position the cursor in a display window and roam the view. These can be used within the 3D View, but the 3D Navigation control is recommended.

The Fit to Page button is only available in Page Layout view, and automatically resizes the page to fit to the extents of the view.

Note If you have a mouse with an ‘active’ wheel, you can also use this for zoom

operations. This is only recommended for use in controlling the Page Layout

View, not the 3D View.

While either the Page Zoom In or Zoom Out options are being used, you can hold down the SHIFT key and the opposite effect is invoked. For example, if you

Zoom In and hold down the SHIFT key, the cursor changes to the Zoom Out

cursor and has the opposite (Zoom Out) drawing effect.

The View Direction toolbar is used to automatically align the view to the selected direction North, South, East, and West or Upwards or Downwards.

Selection of any of these four buttons rotates and aligns the Discover 3D view to be along the direction selected. For example, clicking the N button orients the view to be looking to the north.

These buttons orient the view to be viewed Upwards or Downwards along the Z (vertical axis).

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Exaggerating the scale

Bounding Box dialog

For Global scaling changes, the 3D Map Properties dialog contains options including:

• Add a title to the map window in Page Layout mode

• Display a bounding box around the 3D data in the map window

• Display colour and size legends when in Page Layout mode

• Apply directional or ambient lighting to map window display

• Apply scaling to map window in XYZ direction

Scaling of individual datasets can also be applied via the relevant Property dialog. This is particularly useful when preserving real world height values (e.g. DEM grids and drillholes), but exaggerating for example geochemical/geophysical grids.

View Modes

The Discover 3D display window varies in appearance depending on the View

Mode. Two view modes are available:

• Normal Mode – This is the default viewing mode. In normal mode, Discover

3D displays the 3D objects using all the available area of the display window and provides the most efficient view of data.

• Layout Mode – In Layout mode you can see how objects are positioned on

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the placement of objects prior to printing. The size and orientation of the page is defined by printer settings specified in the File>Page Setup option You may switch between Normal and Layout views quickly by using the Page Layout button or from the Window menu option.

Menus

Discover 3D contains the following pull-down menus; most of the menu functionality is duplicated in the related Toolbars:

• File - File handling for project sessions and access to external databases is

controlled using the options on this menu item. Setting of printing and exiting are also available.

• View - Options to display the various view modes, toolbars and control

dialogs, status bar and property dialogs.

• Insert – Permits graphical objects to be inserted into existing 3D map window displays. These menu commands are also duplicated on the Data Object toolbar.

• Features – Import and Export of vectors in feature databases including DXF

files,

• Tools – Provides options and customisation of Discover 3D settings. Also

provides access to tools such as Grid Flipper.

• Help - On-line help and reference facility.

• Utilities – Additional Discover 3D add-on modules including Fly-through

Wizard, Solid Generator and DXF utilities. See Appendix A for full descriptions of menu items.

Workspace Tree

The Workspace Tree is the main means of control used in Discover 3D. The Workspace Tree operates by listing ALL objects shown in a display. These entities are listed as a hierarchy with various tree branches.

The Workspace Tree is also replicated in the Discover Enhanced Layer Control

(ELC), automatically adding 3D window icon (in addition to the present Mapper and

Browser icons) with all relevant branches listed beneath it. This mirrors the functionality of the Workspace Tree, except for a few submenu options.

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Each branch of the tree is subordinate to a higher branch in the hierarchy such that control properties of a higher branch overrule the same properties of a lower branch when they occur. The Workspace Tree grows incrementally as various objects are added or changed.

To the left of each subordinate branch is a small or box. These boxes indicate lower levels exist for that branch. By clicking on these boxes you can expand their content as shown here for the previous tree. When this is done, additional control branches and data sources appear. The icons to the left of each branch control the visibility, editability, and selectablilty of each layer as the same as in the Discover Enhanced Layer Control window.

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Right mouse button control on

Menu display Options available

3D Map Branch

Display properties of the 3D Map or any subordinate branches. Add axes or add

additional data objects such as drillholes, raster images etc. Open the Fly-through Wizard.

Data Object Branch

Properties and Delete options are available.

Relates to all Data Objects

Surface Branch

The Grid Flipper tool can also be accessed.

Colour Legend Branch

The Data Limits can be reset, and a Size Scale added.

Floating Colour Bar

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Inserting datasets

• Data Objects – allows addition of various data types to 3D view.

3D Session File

Sessions and project management is controlled by the File>Open Session, Save

Session and Save Session As items. Discover 3D uses binary session files to

save and restore projects. Within the session files the following information is stored:

• Path(s) to the necessary data source information.

• Path(s) to any used object, raster and bitmap files.

• Path(s) to drillhole databases.

• Configuration data for open windows and components, their attributes and

properties.

• Session files are usually saved with the file extension .EGS.

The session files do not contain data, objects or bitmaps. Consequently, if a session is opened but the data or object access is not available, the software will

not be able to restore the session completely. A message is displayed in this

circumstance indicating which source file is unreadable.

Session file restoration has a lost file recovery mechanism. If Discover 3D cannot locate some data or other necessary files, it alerts you and offers the option of browsing for them. This applies to all component file types that may have been saved with the session. The following message appears.

Message displayed if a component of a session file cannot be read

In the event that the requested file is not available, from the Open File dialog, select the Cancel button and the session will continue through its list of files to restore what it can. If other files are not accessible, the above message is repeated.

Properties Dialogs

From the Workspace Tree every branch can have its properties controlled by either:

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• Selecting any branch in the workspace tree and click the right mouse button.

The Properties menu item accesses the relevant Properties dialog.

• Double click the relevant item in the Workspace Tree with the left mouse

button.

• Select the Workspace Tree branch and then click the Properties button.

In most cases, the Properties dialog has tabs displayed at the top. Each tab controls a separate aspect of the item selected.

The Properties dialog and assorted tab controls

If the Auto Apply option is disabled, changes to properties are not made until the

Apply button is clicked. This is a useful feature that enables changes in various

tabs of a Properties dialog to be setup before they are applied (particularly for large datasets where redraw times may be significant). If a mistake is made while entering changes, select the Restore button to return the control settings to their original state. In contrast, enabling the Auto Apply option will apply any changes immediately. Property changes can also be applied by clicking the OK button, which will also close the dialog.

Each object branch in the Workspace Tree has a Show/Hide check box. To turn of the visibility of an object branch in the 3D display window uncheck the

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Show/Hide box. Turning off the visibility for an object branch will also turn off the

visibility of any sub-branches.

Display 3D Axes

Three dimensional displays are powerful tools that assist the understanding of the positions of such things as drillholes, sections, geological features, etc; but they require a clear understanding of their location both in easting/northing and depth. Discover 3D allows you to add axes in 3D displays to locate such features. Select the Insert>3D Axis menu option. The primary axes (East – X, North –Y and Depth – Z are drawn into the display.

The Workspace Tree, 3D display showing axes and Internal 3D Axis dialog

The 3D Axis dialog can be displayed from the Properties of the tree branch. This dialog allows you to control all aspects of the displayed axes. You have control for:

• Axis location (Left/Right/Centre), (Front/Back/Centre) or

(Top/Bottom/Centre)

• Axis labelling, font and frequency

• Axis line and increment style (major and minor linework)

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3D Cursor Plane

The 3D Cursor Plane mode allows the user to identify the 3D coordinates of any point in the 3D window. Clicking the Show 3D Cursor Plane button will display the default Cursor Plane location surrounded by a bounding Focus Box.

3D Cursor plane display with bounding box, 3D Cursor crosshairs (red) and associated coordinates in the bottom right

Use the Select /Navigate button to enable the 3D Cursor within the plane (default display is red cross hairs). Moving the mouse will move the crosshairs

accordingly, with the corresponding X, Y & Z coordinates for the crosshair position displayed in the status bar (bottom right of the 3D window). This mode is

particularly useful for aligning the cursor plane with imaged cross-sections. The selected image’s name is displayed at the bottom left of the 3D Window. With the Select button enabled, use the mouse to rotate the view and the mouse wheel to alter the zoom.

Alternatively, use the 3D Navigation button to control the view, reselecting the

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The orientation of the cursor plane can be controlled via the options below. Up / Down (↑↓)

keyboard cursor /arrow keys

Controls the dip of the cursor plane (rotates it about a line located in the XY plane)

Left / Right (← →) keyboard cursor

/arrow keys

Controls the azimuth of the cursor plane (dip is constant) PageUp / PageDown

keyboard buttons

Shifts the cursor plane laterally (plane is kept parallel to but shifted left or right (or up or down) from it’s current position, maintaining dip and azimuth)

Switches the cursor plane between the X, Y and Z planes.

Bonds the cursor plane with that of the selected georeferenced image. Locks the cursor plane in its current position when editing features.

The Toggle Transparency Clipping button allows all data in front of the cursor plane to be made transparent, allowing a clear view of the data intersected by the plane.

Shrink

Enlarge

Fit

The Focus Box provides a 3D visual reference for controlling the cursor plane. It can be resized using the Shrink and Enlarge buttons, or resized to the current view using the Fit button.

The Edit Cursor Plane Properties button enables the appearance of the cursor plane and focus box to be adjusted.

Options include:

• Line colour and thickness

• Cursor plane fill colour and opacity

• Display of the 3D cursor as either 2D or 3D crosshairs

• Manual input of parameters to control the cursor plane position and

orientation

• Focus box size

Feature Toolbar

The Features toolbar provides the controls for the creation, editing and selection of Feature Objects onto the Cursor Plane. This enables the user to digitize points, polylines and polygons directly into the 3D environment to create objects representing geological interpretations, orebody outlines, faults and alteration zones for example. The Feature Objects can then be used in the 3D Solid Generator utility to create a 3D solid by interpolating between each object.

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A Feature database (cosmetic or created) must be editable for the Feature toolbar to be enabled. The following controls are available:

Confirm New Feature - Option to display a dialog after each feature object is created to enable input of attribute data.

Select Feature - Create a selection region to select all Feature Objects that

intersect or lie within this region. This selection region is independent of the Cursor Plane. It is drawn in the screen plane and will select all objects below it. The selected object attributes are listed in the Data tab of the Information Sheet.

The Select/Navigate mode on the Zoom Controls Toolbar can also be used to select individual objects. Used in tandem with the keyboard CTRL key enables the selection of multiple Feature Objects.

Create Point - Digitise a point symbol by clicking with left-mouse button at the

desired location on the Cursor Plane.

Create Line - Digitise a polyline on the Cursor Plane by clicking on a series of

discrete points or holding down the left mouse button and moving the mouse to create a continuous curve. Double click to complete the polyline.

Create Polygon - Digitise a polygon on the Cursor Plane by clicking on a

series of discrete points or holding down the left mouse button and moving the mouse to create a continuous curve. Double click to close the polygon

between the first and last points.

Edit - Display and edit nodes for a selected object. Select individual nodes for

editing using the Select/Navigate mode on the Zoom Controls Toolbar.

Delete selected nodes by pressing the keyboard Delete button or move a

selected node by holding down the left mouse button and dragging it to a new location.

Activate Elasticity - When this option is enabled and a selected node is

moved to a new location neighbouring nodes are moved as well. Elasticity is configured via the adjacent pull-down arrow. The Radius controls which neighbouring nodes are affected by the move. This dialog also contains options controlling how the affected nodes are moved - this affect is represented graphically next to each option (Gaussian, Square, etc).

Feature Information - Similar in function to the Select/Navigate tool. If

multiple objects exist at the cursor location the objects are displayed

individually in the Data tab of the Information Sheet (i.e. the Data tab display cycles through each object, rather than listing all object information at once).

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Snap to node – Allows the current object’s node (new object or editing an

existing object) to be snapped to an existing object’s node. Upon activation, the cursor will change to a circle in the middle of the cross-hairs; when the cursor is close to an existing node, it will change to the standard cross hair; left click to snap to this node.

To the right of the Snap toolbar button is a pull-down options dialog. This allows the Pixel Tolerance to be set (i.e. how close the cursor needs to be to an existing node before it can be snapped to that node). A high-pitched audible

Beep (dee) can also be enabled for when the cursor is within the set pixel

tolerance, when the cursor moves outside the tolerance, a low pitched doh will sound. The Duration of these beeps can be set in milliseconds.

Further keyboard/mouse combinations can be found under the Click Tips tab of

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3D Raster Images 23

5 3D Raster Images

View Map in 3D

Any data displayed in a MapInfo map window can be visualized in the 3D environment as a georeferenced bitmap image (*.egb) i.e. a correctly positioned raster image. This is a very simple and quick way of displaying a lot of data in 3D, however the data is displayed purely as image pixels; any data attributes are lost (e.g. soil copper values) and individual object and datasets properties cannot be altered (e.g. line or point colour and styles).

The Discover3D > View Map in 3D option opens the Discover 3D Map Wizard, from which the desired map window is selected. The 3D Surface sub-window has two options for the height (z) attribute of the output 3D image; either a fixed height (flat) option, or selection of a grid file over which to drape the image. Right clicking in an open mapper and selecting View in 3D will open the same dialog without the need for map selection.

Exercise 5.1 Import a MapInfo map window view into 3D

Data Location: Training 3D\Topography and Training 3D\Geology

1. With Discover running, open the CopperHill_AMG55_AGD66.TAB,

Geology_fill.TAB and Geology_lwk.TAB files into the same map window.

2. Note that the extents of the grid are significantly larger than the geology

vector information. If this grid is used to drape the geological information in 3D, the resulting .egb file would encompass the extents of the largest input dataset, in this case the grid file. To prevent this, draw a polygon in the cosmetic layer encompassing just the vector data, select it and clip the grid to this polygon (use the Surfaces>Grid Utilities>Clip tool). Call the resulting grid CH_Topography_Clip.

3. Add the geological layers to the new map window with the

CH_Topography_Clip grid. Turn the visibility off for the grid, and resize and zoom the mapper window so that the Geology view fills the map window display

4. Right click within this mapper window and select the View in 3D option. In

the View in 3D dialog, select the Grid option, and ensure that the

CH_Topography_Clip file is selected in the adjacent drop-down box. Click

OK. Note that the Discover3D>View Map in 3D menu option can also be

used.

5. Discover 3D will open in a separate window, and display the geology

overlying the topographic surface.

6. In the Workspace Tree to the left of the main view window, double-click on

the 3D Map branch to open the 3D Map Properties dialog. This allows the global control of various 3D attributes. For instance under the Scale tab, adjust the Z axis scaling using the slider to accentuate the vertical scaling of the image. Click Apply to apply the changes.

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7. To navigate around the 3D display, click the 3D Navigation button in the

toolbar. Hold down the left mouse button and move the mouse to rotate the view about the viewing centroid. Hold down the right mouse button and move the mouse up and down to adjust the zoom aspect. Holding down both mouse keys allows movement of the viewing centroid in the X-Y plane, whilst holding down the SHIFT key allows movement of the viewing

centroid in the Z plane.

8. Right-click on the 3D Axis branch of the Workspace Tree and select the

Properties option. This opens the 3D Axis Properties control dialog, in

which the axis display options can be adjusted. Under the Ticks tab, deselect the ‘Show ticks on the axis planes only’ option and click Apply. Alternatively, unticking the 3D Axis branch will make the axis invisible. This can be useful for printing, when having a grid in the background clutters the display (e.g. of drillholes).

9. Right-click on the main Images branch in the Workspace Tree and select

Delete Images to remove the geology raster from view.

Note The output image quality is dependent on the map window size: a larger map

window zoomed to the extents of the dataset will result in a higher resolution image in Discover 3D. The screen resolution can also be increased to improve the quality of the output image, by selecting the Display tab of the

Discover3D>Options menu item, and increasing the Create Raster Images at

value (default value of 2x). Note however that this will increase the size of the output image, thereby reducing the redraw speed within the 3D environment, particularly when viewing multiple images.

3D Display Wizard

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3D Raster Images 25

Exercise 5.2 Import a MapInfo map window view using 3D Display Wizard

1. Re-position the map window used in Exercise 1 to show a different view and

select the Discover3D>3D Display Wizard menu option.

2. Use the wizard to select the underlying grid file and open the image into a

3D window.

3. Close the Geology_fill and Geology_lwk tables and delete the Images

branch from the 3D Workspace Tree.

Overlay Image on Grid

The Discover>3D Utilities>Overlay Image on Grid utility is specifically designed to drape existing raster images over a topographic grid and view in Discover 3D.

Exercise 5.3 Import into 3D an airphoto image draped over a topographic surface.

Data Location: Training 3D\Topography

1. Open the Airphoto.TAB and CopperHill_AMG55_AGD66.TAB files into the

same map window. Resize and zoom the mapper window so that the Airphoto view fills the map window display.

2. Select the Overlay Image on Grid option from the Discover3D>3D Utilities

menu and note the path of the Output EGB file.

Insert Image directly into 3D

Images can be imported directly into an open 3D window if they already are in EGB format. EGB images can be added using the Insert>Images menu or the Add

Image button from the Data Objects toolbar.

When either of these options is selected within a 3D window an Image branch is added to the Workspace Tree. Right-clicking on this branch and selecting

Properties opens the Image Properties dialog, from which a georeferenced bitmap image can be selected.

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Insert menu

Data Objects Toolbar

Exercise 5.4 Display an Image EGB file from Discover3D

Data Location: Training 3D\Topography

1. Select the Add Image button from the Data Objects toolbar within Discover

3D to add an Image branch to the Workspace Tree.

2. Right-click on this branch and selecting Properties opens the Image

Properties dialog.

3. Browse to Training 3D\Topography directory and select the Airphoto.egb file

created in Exercise 5.3. Note that colours can selected to be imported as transparent which is useful if an image has, for example, black or white space around it when it was captured. Alternatively, apply a transparency factor to the whole image or offset the image by a set distance from the DTM grid.

4. Close all data sets in the 3D window.

Georeferencing Wizard

An existing non-EGB image can also be georeferenced by using the Image

Registration Wizard within this dialog.

Multi Section Creator

Multiple scanned regional cross sections (eg those accompanying geological survey 1:250,000 interpretive geology maps) can be easily displayed correctly located in 3D, provided they are accompanied by a table of polylines tracing the X/Y extent of each cross section.

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3D Raster Images 27

Exercise 5.5 Create and display multiple georeferenced regional cross sections in 3D Data Location: Training 3D\ Geology\Regional Cross Sections

1. Drag and drop the FactGeol_DTM.egb into the 3D window. This represents

the fact geology in zone 54 of South Australia (data courtesy of PIRSA).

2. Open the CrossSection_Extents.TAB file into MapInfo as both a browser and

a map window. This table contains multiple polylines representing the spatial extents of 9 scanned regional cross-sections, as contained within the data directory. Note that each polyline has the following information: a section name (directly referencing a PNG image file), a top and a bottom RL value. These fields are compulsory for the process to function correctly.

3. Select the Discover 3D>3D Utilities>Multi Section Creator to open this

tool.

4. Ensure that the various dialog boxes are populated as below. Note that the

Format option indicates the source image type, in this case PNG images. This tool can only process one image type at a time. The type option controls whether a single EGB file is created for all sections, or whether a separate EGB file is created for each section. Click OK.

5. Browse in Windows Explorer to the output directory, and drag the newly

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View Vector Data as 3D DXFs 29

6 View Vector Data as 3D DXFs

DXF files (Data Exchange Format) are a proprietary but widely used digital file format (ASCII or binary) for describing 2D and 3D spatial vector data, developed by Autodesk Corporation. They are a very efficient method of displaying large point, line or region datasets within the 3D environment; this is however at the expense of colour modulation.

It is recommended to display data such as gridlines, infrastructure (roads, streams), contour lines and flight lines as DXFs rather than images, which are far more memory intensive and have fewer display options.

Import 3D Vector File

From within the Discover 3D window, existing DXF files (eg the output from a modelling program) can be displayed using the Add Vector button or Insert>3D

Vector menu option. The following exercise gives an example of their use. Exercise 6.1 Import various 3D DXF vector files.

Data Location: Training 3D\Structure

1. Select the Add Vector button from the toolbar and double-click on the

newly added Vectors branch in the Workspace Tree to open the Vectors

Properties dialog.

2. Under the File tab, click the Open File button and open the

Interp_Structures.dxf from the above data location. Under the Transparency

tab, adjust the Transparency slider to a suitable level and click the Apply

button to view the changes. Readjust as necessary.

3. In the Surface tab, enable the Override fill colour options for a number of

components, and adjust these in the adjacent colour boxes. Click OK to finish.

4. A quicker method for importing DXF files is simply to drag the file from

Windows Explorer into the Discover 3D window. Try this using the Isosurface.DXF file from the Geochemistry folder.

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Import Objects from Table or Selection

MapInfo vector data such as points, lines and polygons can be displayed in Discover 3D as DXF files using the Discover 3D>View Objects in 3D menu option. A separate Vector branch is created for each dataset within 3D window, allowing each dataset to be coloured separately.

Exercise 6.2 Display selected map objects as 3D vectors. Data Location: Training 3D\Topography

1. Open the CopperHill_AMG55_AGD66.TAB grid and

Rivers_AMG55_subset.TAB into a map window. Also open the

Streams_Mol_subset.TAB from the Geochemistry folder also into this window.

2. Select Discover 3D>View Objects in 3D to display the View objects in 3D

dialog. Highlight the Rivers_AMG55_subset table. In the Assign Z value area tick the From grid option and select the surface grid from the Grid pull-down list. Click OK to display in 3D.

3. Use the View Objects in 3D tool to display the Streams_Mol_subset.TAB in

3D. Note that this table already has an RL field; use this as the Z value by ticking the From field option (and deselecting any other options) and selecting this field from the pull-down list. Click OK to display in 3D.

4. Within Discover 3D, open the 3D Map Properties dialog (double click on the

3D Map branch), select the Scale tab and exaggerate the scale display to better visualize the topography.

5. Note however that the stream samples cannot be labelled or have their

symbol display altered (size or colour modulation). This is covered in the next topic.

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View Vector Data as 3D DXFs 31

Creating 3D Extrusions

MapInfo vector data can be extruded to form ‘solid’ 3D DXFs. For instance, a map of the surface traces of a series of faults could be extruded by a fixed distance underground to visualise these faults at depth, perhaps in tandem with a drillhole subset. A MapInfo table of polygons representing building outlines could be extruded by values in a ‘building height’ field, and perhaps coloured using a ‘type’ field.

The Discover 3D>3D Extrusion Wizard menu option enables all map objects within a MapInfo table to be displayed in Discover 3D as a 3D Vector/DXF file.

Exercise 6.3 Extrude the selected fault trace map objects as ‘solid’ 3D vectors. Data Location: Training 3D\Structure

1. Open the Prospect_Structure.TAB and DEM_5m.tab grid into a map

window.

2. View the table in a browser window. Note the Dip_Dir, Dip and Generation

fields. These will be used to control the orientation and colouring of the output DXF objects.

3. Select the Discover 3D> 3D Extrusion Wizard. Tick the Enable

sun-sampling in input data option in Step 1 of the Extrusion Wizard dialog, and

click Next.

4. In the Step 2 dialog, ensure the Primary Z value is set as 0, and tick the

Plus grid value option. Use the open file button to browse for the

DEM_5m.ers grid file located in the Training 3D\Topography directory. Click Next.

5. In the Step 3 dialog, set an Extruded Z value of -200, and tick the Z

Relative to Primary Z option. Click Next.

6. In the Step 4 dialog, enable the Specify an Azimuth and Dip option. Tick the

Use Azimuth Field option, and set this to the Dip_Dir field. Tick the Use

dip/tilt field option, and set this to the Dip field. Click Next.

7. In the Step 5 dialog, enable the Modulated by field option, and assign this

the Generation field. Choose a Colour table eg pseudocolour. Click Next.

8. Click Apply to display the output DXF in the 3D Window. Doing so will keep

the Extrusion Wizard dialog open allowing changes to be easily made and reapplied. Clicking OK will apply changes and close the dialog.

9. Double-click on the Vectors branch in the 3D Workspace Tree to open the

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Viewing 3D Point and Line Data 33

7 View 3D Point and Line Data

View 3D Point Data

The Discover 3D>Create 3D Points option requires an open MI point data table, in which each record has an X (Easting), Y (Northing) and Z (RL) field. If a point dataset does not have a Z/RL field, but a topographic surface grid field exists for the data area, use the Surfaces>Assign Values from Grid option to assign elevation data.

Specify the desired points dataset in the following Show 3D Points dialog. A *selection* option is also available for the display of a previously selected (in a MI mapper) smaller subset of the main dataset.

Right-clicking on the Points branch in the Workspace Tree in the 3D Window will access the Properties option. The Points Properties dialog allows the display of the points dataset to be altered through field and symbol selection, applying transforms and decimation.

Exercise 7.1 Display geochemical sample data as points. Modulate their colour and size, apply

labels and set scaling and offset factors.

Data Location: Training 3D\Geochemistry

1. In MapInfo, open the combined_soilsamg.TAB file.

2. Select the Discover 3D > Create 3D Points option, and select this table

from the list. Click OK to display in the 3D window.

3. To colour the point symbols by copper values in Discover 3D, double-click

on the Points 1 [combined_soilsamg.TAB] branch in the Workspace Tree. This will open the Points Properties dialog. Select the Symbols tab, tick the Modulate Colour option and select the Cu field in the adjacent drop-down window. In the Legend/Lookup Table drop-drop-down window below this, select the DHAssay_Cu table, and click Apply.

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4. To vary the size of the symbols based on a field values, tick the Modulate

Size option in the Symbols dialog. Assign a field from the drop-down list (eg

Pb), and enter an appropriate size range. Click Apply. Combined with the

Colour modulation set in step 3, this is an excellent way to apply bivariate

mapping in the 3D environment (one attribute modulated by colour, the other by size).

5. Labels can be quickly applied using the Label tab. Tick the Show Labels

option, and choose the Cu field. Click the Format button, and set a ‘ppm’ suffix. Set a Label Skip Factor of 5 (1 in 5 labels will be displayed).

6. The Transform tab allows a Translation factor to be applied to the dataset.

This is a useful way to offset the data from a surface grid to allow data of low values to be made visible (eg with an offset of say 10m applied). Return to MapInfo, and with the DEM_5m grid table open, display it in Discover3D using the View Surface in 3D option (this option will be explained fully in the next section). Return to the 3D window, and note the some data is obscured by the surface grid. Go to the Transform tab of the Points Properties dialog, and select a Scale and Translation Transform from the pull-down list. Assign a Translation of 3 and click Apply. Zoom into the point dataset; the data has now been moved a little above the DEM surface, and is now not obscured by the surface grid. When finished, reset this to No transform.

7. Another useful way to view geochemical data is to set the assay value as

an Offset. Go to the Fields tab of the Points Properties dialog. Set the Offset to Cu, and click Apply. This will display the data across a very long Z axis. To alter the offset scale, click the Advanced Options button adjacent to the Offset field. Choose the Transform tab, and after selecting a Scale

and Translation transform, set the Scale as 0.2. Click Apply.

8. The Decimation tab allows the dataset density to be reduced for very large

datasets where rendering performance is an issue. Select the Fixed rate

decimation option, and set a value of 5 (i.e. 1 in every 5 points will be

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Viewing 3D Point and Line Data 35

9. In a similar fashion to the ELC, you can control the visibility of branches by

deselecting them in the Workspace Tree.

10. Use File>Close All to close all open 3D data.

The Add Points button adds extra point branches to the Discover3D Workspace

Tree. However it requires an open 3D point dataset (imported via the View Points

function); it cannot import datasets into the 3D window.

View 3D Line Data

Line data generally refers to data that has been collected systematically along linear traverses with samples or measurements taken at discrete intervals. The data format is exactly the same as a point data table except whereas point data is displayed as individual points in Discover 3D, line data is represented by a single linear feature for each sample line. Line data tables require each record to have an X (Easting), Y (Northing) and Z (RL) field along with a line identifier field.

Geophysical survey line profiles are an example of a line data file that can be viewed in Discover 3D.

Open a line data table into a map window. To view only a subset of the line data table make a selection in the map window. The Discover 3D>Create 3D Lines option will open the Discover – Show 3D Lines dialog, which allows selection of either a lines dataset or selected subset thereof (*selection*).

The Add Lines button in the 3D window adds a Lines branch to the Workspace

Tree. Open the Lines Properties dialog by right-clicking on a Lines branch and

selecting the Properties option. The Lines Properties dialog allows manipulation of the line dataset display, including labels, line style and individual line selection. However it requires an open 3D line dataset (imported via the View Points function); it cannot import datasets into the 3D window.

Exercise 7.2 Display geochemical sample data as Lines. Alter the appearance of the Line

display.

Data Location: Training 3D\Geochemistry

1. From the Training3D\Topography folder, open the DEM_5m grid and

Airphoto files into a new MapInfo map window, and make the DEM_5m grid invisible. Use Discover3D>View Map in 3D to drape the air photo over the grid file in the 3D window.

2. Within MapInfo, note that the combined_soilsamg.TAB file contains a Line

field. Use the Discover 3D>Create 3D Lines option and select this table from the list. Click OK to display in the 3D window. Discover3D will display a Define Database Fields dialog prompting for the Line field. Assign the Line field.

3. In the Points Properties Fields tab, assign the Cu field as the Offset.

Again use the Advanced Options button and set the Scale factor to 0.2 under the Transform tab. Click OK twice to apply this scaling factor.

4. In addition to the Points Properties tabs, the Lines Properties dialog has a

Line Style and 3D Line Style tab.

5. The 3D Line Style tab controls the cross-sectional shape of the lines, and

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the 3D Tube option, and select a Tube Shape from the list. Alter the

Thickness, and click Apply.

Custom tube shapes can be used via the Import New Shape option built into the Tube Shape Manager found in the Utilities menu: this will import any shape drawn in a MapInfo table.

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Gridded Surfaces 37

8 Gridded

Surfaces

The Discover Surfaces module provides a rich suite of functions and tools for creating and analysing gridded surfaces. The Surfaces module has been designed to integrate seamlessly with gridded data created externally from MapInfo and with other Discover modules that use gridded data such as Drillholes.

What is a Surface Grid?

A surface grid is a rectangular array of points, each of which has an interpolated Z or height value. The Z value in a grid may represent either real heights (such as topographic elevation, depth to weathering or coal seam thickness) or may represent a geochemical, geophysical or other value (such as gold concentration, radiometric total count or rainfall).

The surface grid is generated from a set of input points each of which have a location and a Z value for that location. The regular surface grid is generated from the irregularly distributed input points by calculating interpolated values at regular positions.

It is important to understand that the interpolated values are approximations only of the real values of the surface and that the interpolated values differ depending upon the interpolation method used. With some interpolation methods, it is possible that the interpolated value is slightly different to that of a data point at the same position.

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Regular grid of interpolated points generated from irregularly distributed input points

Once a regular grid of interpolated values has been calculated and stored, it can be displayed in MapInfo. The grid can be displayed as a set of rectangular polygons, each one representing a grid cell. The advantage of this method of display is that the MapInfo standard tools for thematic mapping and querying can be used with the grid. Although Discover does allow grids to be created in this format, the major disadvantage is that of file size and display speed.

If the grid cells are stored in a simple binary format, then Discover can display them in MapInfo as a raster image. This method of display is significantly quicker than for polygon grids and allows large grids to be handled efficiently.

A third way in which a grid can be displayed is as contours. Contours are generated by tracing lines of equal Z value across the grid. The contour lines do not provide as much information as a grid, but do offer another visualisation method. This is useful for displaying contours of one grid over a second grid (for example, soil geochemistry contours over a magnetics grid).

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Gridded Surfaces 39

Configuring Grid File Formats

Discover>Configuration>Grid Handlers

When grid formats are created, imported or exported, the Discover Surfaces module can assist these operations by:

• Creating grid surfaces in a preferred format

• Exporting a grid in a preferred format

• Internally using the preferred grid format to allow ease of use when MapInfo

is used with third-party software packages (such as ER Mapper, Vertical Mapper, Surfer or Oasis Montaj™ by Geosoft).

The preferred grid format can be specified from the

Discover>Configuration>Grid Handlers menu item. Use the Grid Format Selection dialog to nominate your preferred grid format.

Once a grid format has been selected, all grids created from this point use the specified format unless an interface option exists to override the setting. You can alter the preferred Grid Handler used by Discover by selecting another at any time.

The following industry standard grid formats are supported by Discover:

• Band Interleaved by Line (*.BIL)

• ER Mapper (*.ERS)

• Geosoft (*.GRD)

• Surfer (*.GRD)

• Vertical Mapper (*.GRD)

• ESRI ASCII Grid (*.ASC, *.TXT)

• USGS DEM (*.TAR)

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• ASCII (*.TXT, *.ASC, *.CSV)

Note The Grid Handler support provided in this option is ONLY available for MapInfo

versions more recent that Version 5.5.

MapInfo Vertical Mapper creates raster-based format grids. A read/write handler for Vertical Mapper format grids is supplied with Discover. All versions of MapInfo Professional 6.0 or later include a read-only handler.

Create Surface Grid

Discover can produce a gridded surface from any mapped data, which has a numeric column representing a z-value or grid channel. Examples of this type of data include topographic spot heights, soil geochemical sample results or

geophysical data such as ground magnetic, or gravity data. Discover can also grid line and polygon data providing there is an associated numeric z-value. Therefore it is possible to create a grid directly from data such as contour lines without having to pre-process the data first and convert the line information into points.

Exercise 8.1 Create an elevation grid from spot height data over the Darlot area

1. Open the DARLOT_SPOT table from the Encom

Training\Darlot\Topography folder and using the Information Tool, query

a few of the spot heights to see the associated data. We will create a grid using the AHD_RL field. The elevation values range from a low of 429.31 to a high of 528.6m. You can check this by selecting Query > Calculate

Statistics and selecting the DARLOT_SPOT table and the AHD_RL field.

2. Select Discover>Surfaces menu. A new Surfaces menu should appear on

the MapInfo Menu Bar. Select Surfaces>Create Grid and select the DARLOT_SPOT layer or right-mouse click on DARLOT_SPOT layer in the

ELC and choose Create Grid.

3. The elevation data is loaded into the Discover Gridding Tool. This utility is

controlled via a series of tab pages to the left of the preview window. On loading the data Discover has automatically computed a set of gridding parameters, however we can modify these according to the data to be gridded.

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Gridded Surfaces 41

4. Select AHD_RL from the list of numeric fields available to grid.

Input Tab

The Input tab summarises the input data and provides a selectable list of all numeric data columns that are available for gridding in the source Tab file or query. Basic summary information is provided for the selected data including the number of points, minimum and maximum field values and minimum and maximum easting (X)/northing (Y) values for the minimum bounding rectangle that fully encloses the input data.

A Breakline table can be selected in order to force gridded data to conform to certain slope requirements in critical areas, eg drainage traces, topographic ridge lines or roadways.

The Coincident points pull-down list contains a number of options to use in the event that there are two or more data points at the same location.

The Data Conditioning option enables you to condition or annotate the data used to grid. The input grid data can be clipped to specified extents, null values can be excluded from the gridding process or converted to background values and minimum and maximum capping values can also be set.

Statistics Explorer

The Statistics Explorer is a utility for examining and understanding the spatial and statistical aspects of a dataset. The Statistics Explorer will be examined in more detail in the next exercise.

Preview Window

View input points in the preview window. Click button to remove input points from view.

View search ellipse in the preview window. Only available if Inverse Distance Gridding method is selected.

Apply a histogram equalisation stretch to the image in the preview window. This button can be used to distribute colours more evenly across the image and is particularly useful for data with poor dynamic range.

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Display images in the preview window as either coloured or monochrome (black and white). This button toggles the image between monochrome and colour. Apply a sun illumination to the image in the preview window. This can be used to enhance detail within a gridded image. The sun angle is fixed from the north-east direction.

Interrogate the quality of the interpolated surface using the Statistics Explorer. Select a look-up table to colour the grid. The chosen colour table will be applied to the gridded image when loaded into Discover.

A pop-up menu can also be accessed by right-clicking with the mouse in the preview window:

5. Click on the Method tab and select Triangulation as the method.

The Triangulation method produces a regular gridded surface through a set of data points by using an optimised Delaunay triangulation algorithm. The triangular mesh is created by drawing lines between adjacent input data points and forming an irregular network such that no triangle edges are intersected by other triangles. A regular grid is then computed from the triangular irregular network and grid cell values computed using a natural neighbour interpolation process. As the original data are used to define the triangles, this method is very useful for situations where the data must be honoured very closely (eg elevation data in a digital terrain model).

The triangulation method is best applied to data that is evenly distributed over the gridded area. If there are large areas of sparse or missing data distinct triangular facets may appear in the output grid. As triangulation uses all the input data to construct the triangular mesh, the only parameter that needs to be adjusted is the grid cell size. Grid cell size can be adjusted to an appropriate value for the dataset.

6. Click on the Geometry tab and leave the default Cell size at 150m.

7. Choose the Output tab and select ERMapper as the output grid format.

Save the grid to the same folder as the input data points and click Save to create the grid and open it into a new map window. Turn off the visibility for the DARLOT_SPOT layer in the map window.

To report grid cell values directly to the screen, choose the Grid Info button from the Surfaces button bar.