Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
I’ve setup Mapnik to connect to a PostGIS database, and display geometry. I’d like to have a column in my database called opacity, and use it as the opacity for that row of geometry when Mapnik renders it.
So far, I’ve only found information on how to display text from the database, and how to use filters to display different styles when database values are within parameters. Nothing about how to use the values directly inside of a style or layer though – is this possible?
Alex, this is not currently possible for opacity, but you can file a ticket at trac.mapnik.org to request it. Basically, in Mapnik trunk (aka Mapnik2), support has just been added to allow “data-driven symbolizers” for attributes beyond text, but opacity is not yet exposed:
http://mapnik.org/news/2009/dec/08/future_mapnik2/