Bug report #19937

Strange blurred squares in vector layers using "outer glow"

Added by Andrew Hamilton about 6 years ago.

Status:Open
Priority:Normal
Assignee:-
Category:Symbology
Affected QGIS version:3.2.3 Regression?:No
Operating System:Mac OS X Easy fix?:No
Pull Request or Patch supplied:No Resolution:
Crashes QGIS or corrupts data:No Copied to github as #:27759

Description

I have a GPS track log of about 8,000km simplified to about 85,000 line segments. If I use the "outer glow" line effect, as the software works its way through the log drawing the tracks, it keeps on superimposing translucent grey squares (see the attached example). This happens even with no background layer. You can see the same result by choosing the "effect neon" built-in symbol.

I've seen this same behaviour on 3.0.2 and 3.2.3

My track log is far too large to attach here, but if anyone needs it to help diagnose something, let me know and I'll figure out how to get it to you.

weird-glowing-squares.png - Example (1.1 MB) Andrew Hamilton, 2018-09-25 11:58 AM

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