Bug report #15337

Updated by Nyall Dawson almost 4 years ago

Scale dependent layer visibility set in layer properties -> general or in style -> rule-based is not working properly in print composer. Layers that are visible in the map canvas are not visible in the print composer layout although same scale is used in canvas and composer. In pdf or image export, there is a similar issue as layers appear or do not appear in exported files differing from composer view. The problem seems to be related to bug report #9648 (closed), where problems like this where predicted by Mathieu Pellerin. As I think that scale dependent styling rules and visibility are very important in any complex map styling, it would be great if there is a solution found for the issue.

In the attached files, I described the behaviour concerning scale dependent visibility between canvas and composer in detail. Therefore I created a simple test project with print composer. From that project I created screenshots and pdf exports and documented the used scale thresholds in a word document. Further details are also given in the word document.

In case the test project seems to show some edgy scenarios, I describe a daily-work issue I experience with the bug: Lets say I want to style a topographic base map with buildings displayed depending on scale. From 1:1 to 1:1,000 I want buildings to show in light grey and 50% transparency. From 1:1,001 to 1:10,000 I want to show buildings in solid dark grey. From 1:10,001 buildings shouldn't show at all. Off course, the user expects to get the same view in map composer and in export files. But with the bug, you will have some strange effects when printing maps from composer with close to threshold scale.

It might also help to take a view to the earlier communication on QGIS-user-mailinglist here: http://osgeo-org.1560.x6.nabble.com/Bug-in-Map-Composer-td5277723.html#a5277953.