Features are not rendered (at certain scales) and cannot be selectd/identified if they have invalid geometries

[qgib]

Author Name: Katharina King (Katharina King)
Original Redmine Issue: 12553
Affected QGIS version: 2.18.4
Redmine category:map_canvas

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New description:
If a vector has invalid geometries such features are sometimes not rendered and usually this also mean that even if rendered are not selectable or identifiable.

Open the attached vector layer and try to:

1. select or identify the polygon on the left to the one with "fsdo name" = Boise FSDO
2. try zoom in to the above polygon, at certain point it will disappear

Old description:
When a vector layer with huge geometry complexity is loaded, the data is not rendered anymore from a specific detailed zoom level on.

Procedure:

1. Open qGis 2.8.1 on Windows 7
2. Set the CRS to EPSG=21781
3. Add the following "vector layer":https://dl.dropboxusercontent.com/u/29729511/Test/Test_GradientGeometry.sqlitedb: The vector data gets rendered
4. Zoom to 1:5000 or deeper: The vector data doesn't get rendered anymore!
5. Zoom back: The vector data gets rendered again

Remarks:

• Zoom level dependent rendering is OFF!
• The same procedure with qGis 1.7.3 on Windows 7 works perfectly... The vector file is OKAY!
• The phenomemon is independent of the vector FORMAT. You can translate to SHAPEFILE, the same happens!

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• FSDO_Service_Areas_111615.zip (Giovanni Manghi)

[qgib]

Author Name: Katharina King (Katharina King)

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Don't understand why 2 lines got canceled in the description above! These are VALID lines... Can't edit anymore!

[qgib]

Author Name: Katharina King (Katharina King)

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Found the reason:
The Vector file holds geometry lines with 0 length! It seems qGis doesn't like that and stops rendering at specific zoom levels.

• This is a very particular behaviour
• Remember that qGis 1.7.3 has no problem with the 0 length geometry lines!

Resolved by cleaning the vector file with GRASS:
@v.clean input=Test_GradientGeometry@Test output=cleaned tool=rmline thres=0.00 type=line@

[qgib]

Author Name: Giovanni Manghi (@gioman)

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• category_id was configured as Vectors
• fixed_version_id removed Version 2.8.1
• operating_system was changed from Windows 7 to
• os_version was changed from Windows 7 to
• version was changed from 2.8.1 to master
• subject was changed from Vector layer not rendered when zooming to Line vector do not show at certain scales if it has geometries with length=0

[qgib]

Author Name: Nyall Dawson (@nyalldawson)

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Can you reshare the sample data?

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• status_id was changed from Open to Feedback

[qgib]

Author Name: Giovanni Manghi (@gioman)

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Nyall Dawson wrote:

Can you reshare the sample data?

better try contact directly the author of the ticket.

As it worked fine in a older QGIS release this is technically a regression.

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• priority_id was changed from Normal to Severe/Regression
• status_id was changed from Feedback to Open

[qgib]

Author Name: Giovanni Manghi (@gioman)

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Will try to manage a new sample dataset to prove this issue. The problem has been certainly seen on 2.14 and 2.18 too.

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• category_id was changed from Vectors to Map Canvas
• fixed_version_id was configured as Version 3.0
• version was changed from master to 2.18.4

[qgib]

Author Name: Giovanni Manghi (@gioman)

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• 10781 was configured as FSDO_Service_Areas_111615.zip
• subject was changed from Line vector do not show at certain scales if it has geometries with length=0 to Features are not rendered (at certain scales) and cannot be selectd/identified if they have invalid geometries

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• FSDO_Service_Areas_111615.zip (Giovanni Manghi)

[qgib]

Author Name: Giovanni Manghi (@gioman)

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• regression was configured as 1

[qgib]

Author Name: Giovanni Manghi (@gioman)

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• priority_id was changed from Severe/Regression to High

[qgib]

Author Name: Giovanni Manghi (@gioman)

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• easy_fix was configured as 0

[qgib]

Author Name: Giovanni Manghi (@gioman)

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End of life notice: QGIS 2.18 LTR

Source:
http://blog.qgis.org/2019/03/09/end-of-life-notice-qgis-2-18-ltr/

QGIS 3.4 has recently become our new Long Term Release (LTR) version. This is a major step in our history – a long term release version based on the massive updates, library upgrades and improvements that we carried out in the course of the 2.x to 3x upgrade cycle.

We strongly encourage all users who are currently using QGIS 2.18 LTR as their preferred QGIS release to migrate to QGIS 3.4. This new LTR version will receive regular bugfixes for at least one year. It also includes hundreds of new functions, usability improvements, bugfixes, and other goodies. See the relevant changelogs for a good sampling of all the new features that have gone into version 3.4

Most plugins have been either migrated or incorporated into the core QGIS code base.

We strongly discourage the continued use of QGIS 2.18 LTR as it is now officially unsupported, which means we’ll not provide any bug fix releases for it.

You should also note that we intend to close all bug tickets referring to the now obsolete LTR version. Original reporters will receive a notification of the ticket closure and are encouraged to check whether the issue persists in the new LTR, in which case they should reopen the ticket.

If you would like to better understand the QGIS release roadmap, check out our roadmap page! It outlines the schedule for upcoming releases and will help you plan your deployment of QGIS into an operational environment.

The development of QGIS 3.4 LTR has been made possible by the work of hundreds of volunteers, by the investments of companies, professionals, and administrations, and by continuous donations and financial support from many of you. We sincerely thank you all and encourage you to collaborate and support the project even more, for the long term improvement and sustainability of the QGIS project.

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• resolution was changed from to end of life
• status_id was changed from Open to Closed