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 menu was updated with a new Help text:
Help text on Geographical coordinates menu
Guide to display geographical coordinates
Use this command object to display a Lat / Lon grid.
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.
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 project was UTM zone 32 Northen Hemisphere the display lines are more slanted.
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:
Unknown macro: {indent}
- 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
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:
Unknown macro: {indent}
- 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