qgisqgis-2rotatesymbology
I have a vector symbol that I am using rule based style with. In the Rule properties tab I click on the SVG marker and change the "rotation" which is a field I have made to handle to the rotation angle I want per each row for this feature. Am I setting this up wrong?
Every record has a slightly different Rotation so when I look at the symbols they should all not be straight up and down.
If you want to use a field in attribute table, you should select the field directly in the Data defined override which has the angle value. The field should be of double/integer type not string field type. In the following figure I used at first Single Symbol and select Data defined override beside the rotation field, as you can see below:
Then, I changed the style from Single Symbol to Graduated and select another field (in your case slope field), as you can see below.
Best Answer
I have created a style that converts symbol angle given in radians*10000 and with 90 deg offset in "SUUNTA". The input field is integer64 having both positive and negative values. 90 - "SUUNTA" /10000/pi()*180
This worked fine with QGIS 3.x but now 3.12.3 using the same style gives random results. First the symbol was always at 90 degrees despite the values. By updating the values range resulted that the direction is there but now 90 degrees offset. After replacing the definition to: 180 - "SUUNTA" /10000/pi()*180 did not change anything, it is still the same 90 degrees offset from the correct value This is weird.