Introduction
Example of a scene with axes, annotation and scalebar
Geographical grids, axes annotation, scalebars and text are natural display features when working out displays and presentation graphics. This chapter gives a brief documentation of the standard menus for text and annotation graphics in the system.
Geographical coordinates with axes
Use the command Geographical coordinates to display axes and coordinate annotation on a dataset.
Geographical coordinates can be accessed as a command (found in Shared Commands > Visualization) or as a stand alone menu from Tools > Geographical Management. In either case the rules for a correct display is the same.
- Push Default display (older version only Display) under Default display to see the default values.
- Type in Longitude/Latitude start, Long/Lat increment and Longitude/Latitude stop values to set a custom geographical grid.
- Push Display or Execute to display geographical coordinates using the Lat / Lon values.
- To get a nice placement of the annotation numbers use the tuning in Adjust annotation numbers.
Sometimes it may be useful to create an item command that will save your settings for a specific dataset. This will save you time next time you want to display axes over the same area. Read more about creating item commands.
Options in Geographical coordinates
The following text is an extract from the Help text activated by the ? symbol on the meny toolbar.
Guide to display geographical coordinates within the graphical window
The first thing to do is to check that the correct coordinate system is set under the Coordinates page.
When this is done and correct go on to get a default display of geographical coordinates.
Push first Default display to get a default display as good as possible. Sometimes the algorithm get a good display,
but normally the user must take care of the detailed settings of start, increment and stop position.
Push Update detailed to get the Lat / Lon values into the number fields and tune them for a satisfactory display.
When pushing Display or Execute the display of geographical coordinates will use the Lat / Lon values.
The geographical axes display will be within the graphical window. To see the graphical window push the Draw Frame icon 
on the toolbar.
Here is a little study of display options and how to get a good display.
A part of the Atlantis project is used to display a map and geographical coordinates. The assumed projection is Mercator, but we will also study the display when assuming other projections.
The default display for Mercator appears OK, but can be improved. Push Update detailed to transfer default values over to the Lat / Lon fields.
Use Adjust annotation numbers to get a better positions of the coordinate numbers. Here the right number was adjusted to -25 and Up to 5. The Longitude start, increment, stop is -14 2 0. The Latitude start, increment, stop is -34 2 24.
To display annotation numbers for every line change the number next to Auto annotation with the tooltip Frequence of annotation number to 1.
We see that the minutes are zero and change Annotation format to DD (Only degrees). At the same we check in for E/W/N/S.
If the coordinate system was UTM zone 32 Northen Hemisphere the display lines are slanted and shows different numbers. This shows that correct coordinate setting is essential for getting a correct display.
The geographical lines was displayed using Default display, but kept the same adjustments of annotation numbers as before.
To get annotation display along all side change default NE to all. For a little display like this it is necessay to adjust all numbers. This particular setting was -25 50 5 -20 for Right Left Up Down.
To get the coordinate lines displayed on the surface one has to check in the Sticky checkbox and also apply Set as sticky surface on the surface grid.
Scale bar
To display a scale bar open Tools > Scalebar display
- Push Draw Scalebar to display the scalebar in default position and appearance.
- To place the scalebar at specific position:
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- Set the screen in 2D mode.
- Tick the box Use XYZ coordinates
- Click in the graphic window where you want to place the scalebar.
- Click Update cursor to world coordinates to get the cursor coordinates.
- Redisplay scalebar by pushing Draw Scalebar
The default scalebar display will be within the graphical window and the drawing size is related to that window. To see the graphical window push the Draw Frame icon on the toolbar.
Text annotation
The Three dimensional text command lets you create text annotation anywhere in the graphical window. You can create 2D or 3D text, display the text in any angle or stick the text to a surface. All these things can be found out whith a little test and trying. When everything is fine save the command object. Optionally save it as an Item command or copy a present CO so you work with and save a copy of the command object.
As an example here are the guide lines for drawing a text at an angle along a line.
Guide lines for text annotation at an angle
- Write in the desired text in the text field.
- Set the screen in 2D mode and make two cursor positions:
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- First cursor position: at end of text
- Second cursor position: at start of text
- If the screen is in 3D mode use y to attach the cursor point to a surface.
- Push Update cursor to coordinates.
- Push Update dip and azimuth. Azimuth is for rotation around z axes. Dip is for 3D mode.
- Check in the Dip and Azimuth boxes.
- Select text attributes.
- Push Execute to display the text.
With a little training one can place text at any angle and position.
Example map with geo grid, scale bar end 3D text