Bug report #12553

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

Added by Katharina King over 4 years ago. Updated 9 months ago.

Status:Closed
Priority:High
Assignee:-
Category:Map Canvas
Affected QGIS version:2.18.4 Regression?:Yes
Operating System: Easy fix?:No
Pull Request or Patch supplied:No Resolution:end of life
Crashes QGIS or corrupts data:No Copied to github as #:20694

Description

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: 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!

FSDO_Service_Areas_111615.zip (2.34 MB) Giovanni Manghi, 2017-03-03 04:16 AM

History

#1 Updated by Katharina King over 4 years ago

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

#2 Updated by Katharina King over 4 years ago

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 [email protected] output=cleaned tool=rmline thres=0.00 type=line

#3 Updated by Giovanni Manghi over 4 years ago

  • Category set to Vectors
  • Target version deleted (Version 2.8.1)
  • Operating System deleted (Windows 7)
  • OS version deleted (Windows 7)
  • Affected QGIS version changed from 2.8.1 to master
  • Subject changed from Vector layer not rendered when zooming to Line vector do not show at certain scales if it has geometries with length=0

#4 Updated by Nyall Dawson about 3 years ago

  • Status changed from Open to Feedback

Can you reshare the sample data?

#5 Updated by Giovanni Manghi almost 3 years ago

  • Priority changed from Normal to Severe/Regression
  • Status changed from Feedback to Open

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.

#6 Updated by Giovanni Manghi over 2 years ago

  • Category changed from Vectors to Map Canvas
  • Target version set to Version 3.0
  • Affected QGIS version changed from master to 2.18.4

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.

#7 Updated by Giovanni Manghi over 2 years ago

  • File FSDO_Service_Areas_111615.zip added
  • Subject 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

#8 Updated by Giovanni Manghi over 2 years ago

  • Regression? set to Yes

#9 Updated by Giovanni Manghi over 2 years ago

  • Priority changed from Severe/Regression to High

#10 Updated by Giovanni Manghi over 2 years ago

  • Easy fix? set to No

#11 Updated by Giovanni Manghi 9 months ago

  • Resolution set to end of life
  • Status changed from Open to Closed

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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