Bug report #14960
effect: anti-aliasing seemingly broken when layer-wide effects enabled
|Affected QGIS version:||master||Regression?:||No|
|Operating System:||Easy fix?:||No|
|Pull Request or Patch supplied:||No||Resolution:|
|Crashes QGIS or corrupts data:||No||Copied to github as #:||22909|
I've just noticed a serious (if one cares about quality of exported composers ;) ) issue with effects. Under a specific symbology composition scenario, enabling layer-wide effects results in pixelated border. If I had to guess what's happening here, it looks like the transparency is dropped, affecting rendering of anti-aliased edge.
The effect_vs_noeffect.png screenshot probably does a better job at demonstrating the issue than my introductory paragraph above.
A test project is also attached to reproduce this issue.
[effect] fix issue with svg marker and antialiasing (fixes #14960)
Credit for original patch to @nirvn
#2 Updated by Mathieu Pellerin - nIRV about 5 years ago
Few more observations:
- The issue is actually triggered by the use of an SVG marker layer; if I have an svg marker layer added, the absence of antialiasing will appear after the first feature is rendered.
- Scarily enough, it affects everything, including polygons (if you end up using centroid fill with an svg marker), lines (if you use an svg marker on vertexes), etc.