Bug report #403
Rendering extremely slow with vector transparency
| Status: | Closed | ||
|---|---|---|---|
| Priority: | Low | ||
| Assignee: |  Martin Dobias | ||
| Category: | Map Canvas | ||
| Affected QGIS version: | Regression?: | No | |
| Operating System: | All | Easy fix?: | No |
| Pull Request or Patch supplied: | Resolution: | worksforme | |
| Crashes QGIS or corrupts data: | Copied to github as #: | 10462 |
Description
Rendering with vector transparency set is intolerably slow if antialiasing is turned off. On a new install, we should set AA on by default.
If someone can confirm this, we should issue a warning when setting transparency if AA is off.
History
#1
Updated by Marco Hugentobler almost 18 years ago
Gary,
This does not happen on my system (Kubuntu 6.10, Qt-4.2.1). Performance is ok
for me with transparency and with/without AA.
cheers,
Marco
#2
Updated by Gavin Macaulay - almost 18 years ago
Works fine for me with Qt-4.2.1 under Linux with most polygons. With very complicated polygons or .shp files with large numbers of polygons I do see a small difference, but nothing that is significantly slower.
#3
Updated by Gary Sherman almost 18 years ago
- Resolution set to invalid
- Status changed from Open to Closed
Perhaps this is an issue with my (and others) X11 configuration.
I'll close this issue.
#4
Updated by Markus Neteler over 17 years ago
- Status changed from Closed to Feedback
- Resolution deleted (
invalid)
I am using Madriva2007 with QT4.2.1 and rendering is indeed extremely slow with vector transparency. Using SVN HEAD.
So I suggest to add a warning about this in case AA is disabled. I take liberty to reopen. In the German translation it is rather impossible to understand what checkboxes should be activated to avoid this slowliness.
Markus
#5
Updated by Tim Sutton over 17 years ago
Im testing with qt4.3 and I cant replicate. In many cases turning on anti-aliasing will actually slow down rendering so I think its going to be very confusing to put up a message saying 'turn on AA to speed up rendering with transparnecy, but AA will slow down rendering.'. Im going to forward this bug to 0.8.2, but I wonder if the preblem is resolved with qt4.3 in which case we should consider recommending this version of qt4.3.
Tim
#6
Updated by Tim Sutton about 16 years ago
- Status changed from Feedback to Closed
- Resolution set to worksforme
Closed - works for me under Qt 4.3 & Qt4.4. Please reopen if problem persists under a current version of Qt4. Suggestions to improve wording of options for clarity in German would be welcome.
Regards
Tim
#7 Updated by Anonymous about 15 years ago
Milestone Version 1.0.0 deleted