I have to do some visualizations in QGIS (1.8.0) and up to now I've been very happy with the new Dialog "Layer Properties -> Style", using the rotation-field to rotate Point-Geometries visualized by a triangular Symbol of the section "Simple Markers".
For me QGIS fails to rotate Point-Geometries with rule-based style. Here what I did:
I've got a Point Layer with a Attribute table with this structure:
ID ; Place ; orientation ; typ ; centrality 1 ; Basel ; NULL ; center ; 2 2 ; Liestal ; 120 ; depending ; 4 3 ; Munzach ; 123 ; depending ; 5
Under the "Categories"-Section I made two categories: 'center' and 'depending'. The Symbol of the depending Place is rotated, using the 'orientation'-column as the rotation field. Now it shows on the center place.
Now I'm trying to use the "Rotation field" in the "Rule-based"-Section which doesn't work for me. I Want to scale the Place according to their centrality.
In the 'rule-based' section I added a rule with the Filter typ='depending' and I disabled the Symbol. then I did 'refine current rule' -> 'add categories to rule'. Here I classified the Column 'centrality' and added my triangular Symbol in different sizes according to the centrality of the place. This works. Now I want those triangles to show to the center place using the -> Advanced -> rotation field -> 'orientation'.
Unfortunately QGIS doesn't apply the rotation field in Layers with 'ruled-based' Symbology.