Using Your Own (Geologic) Symbology
Geoff has made the Vertex-Symbols Plugin which allows you to load your own svg graphics and use it as point symbol. His Vertex Symbols Plugin can be downloaded here
How to rotate symbols according to an attribute value
This tip is very useful for geologist since many point symbols (planar, linear and fold structures) must be rotaded according to the azimuth (dip or plunge direction). This solution doen't require extra plugins. It only uses the label style function of Openjump. Any kind of installed fonts can be used as a point symbol in the OpenJump workbrench. I post a special font set for geologist with a sepatate reference table (Geological_Symbols.TFF and Reference_Table.pdf download here as zip-file).
1 - First of all, print the Reference_Table.pdf. This reference table help you to know corrispondence of each geological symbols to regular alphabet ("a" is symbol 1, "b" is symbol 2, etc).
2 - Create a new point dataset (ex. geological_points.shp) with two attribute values:
- (SYMBOL) for the type of symbol, for each symbol I give the regular letter of the alphabet
(a,b, etc), according to the Reference Table.
- (AZIMUTH) for the azimuth, with values between 0° and 360°.
Remember that OJ label style calculate the rotation in anticlockwise direction. If the azimuth of your geological symbols is clockwise, please correct the values, entering your azimuths as a negative value
3 - In OJ go on Change Style>label and change these options:
- "Enable labeling" = enabled
- "label attribute" = SYMBOL
- "angle attribute (degrees)" = AZIMUTH
- "Height" = at least 20 or more
- "Change Colour"= set the colour you want for your symbols
- "Change font..." = Geological Symbols
4 - On Change Stle>Rendering uncheck both "Fill" and "Line" to avoind that vertex overlaps symbol
5 - Click on "OK" ... and magically you see your geological fonts displayed on the OJ workbench view with the right orientation
Using this technique you can display whatever symbols you use, not only geological (if translate to a Font set) and you can rotate them.
If you want to use a different symbol font, remember always to print its reference table, using a font editor software (see How to have a reference table from your favorite font symbols).
Since the OJ label style is used as a "symbol displayer", you can't display other label close to your symbols. But a duplicate of your point dataset (with a (LABEL) attribute) can be used as label layer, instead.