Bug report #12300: Rendering issue with transparent WMS layers - QGIS Application - QGIS Issue Tracking

Bug report #12300

Rendering issue with transparent WMS layers

Added by Roel Huybrechts over 9 years ago. Updated over 9 years ago.

Status:	Closed
Priority:	Severe/Regression
Assignee:	-
Category:	Web Services clients/WMS
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 #:	20478

Description

When setting the transparancy of certain WMS layers the rendering goes wrong and colors are off. According to my limited testing, it happens only on WMS layers that already have transparency on their own, opaque layers render correctly after applying transparency.

Steps to reproduce:

Connect to this WMS service in QGis (tested on 2.9 master): https://www.dov.vlaanderen.be/geoserver/gw_varia/verzilting/wms?version=1.3.0&request=GetCapabilities
Load the (only) layer 'verzilting'
The colors are correct.
Go to the layer properties, set transparency to a value != 0

Result:

The layer is not transparent and the colors are all wrong.

Associated revisions

Revision dbfbc692
Added by Martin Dobias over 9 years ago

Fix transparency for WMS layers (fixes #12300)

Revision 507b9f22
Added by Martin Dobias over 9 years ago

Fix transparency for WMS layers (fixes #12300)

(cherry picked from commit dbfbc692838e768b13c970c7d777829883b4b841)

History

#1 Updated by Roel Huybrechts over 9 years ago

Apparently something went wrong pasting the WMS link, the correct version is: https://www.dov.vlaanderen.be/geoserver/gw_varia/verzilting/wms?version=1.3.0&request=GetCapabilities

#2 Updated by Giovanni Manghi over 9 years ago

Category set to Web Services clients/WMS

#3 Updated by Giovanni Manghi over 9 years ago

Status changed from Open to Feedback

confirmed. This was an issue also in previous qgis releases?

#4 Updated by Roel Huybrechts over 9 years ago

Yes, I can reproduce it in QGis 2.8 and 2.6, if needed I can test in previous versions as well.

#5 Updated by Paolo Cavallini over 9 years ago

Subject changed from Rendering issue with transparant WMS layers to Rendering issue with transparent WMS layers

#6 Updated by Giovanni Manghi over 9 years ago

Roel Huybrechts wrote:

Yes, I can reproduce it in QGis 2.8 and 2.6, if needed I can test in previous versions as well.

I would appreciate that, thanks!

#7 Updated by johanvdw - over 9 years ago

Giovanni Manghi wrote:

Roel Huybrechts wrote:

Yes, I can reproduce it in QGis 2.8 and 2.6, if needed I can test in previous versions as well.

I would appreciate that, thanks!

I can confirm the problem in QGis 2.4 (debian jessie, QGis provided by debian).