Bug report #8067

layer with cylindrical equal-area projection does not render correctly

Added by Brian Sipos almost 7 years ago. Updated about 1 year ago.

Status:Closed
Priority:Normal
Assignee:-
Category:Projection Support
Affected QGIS version:master Regression?:No
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 #:16906

Description

I am importing some line-string data along with a set of political-boundary reference lines as separate layers. When I load the data in QGIS 1.7.4 the layers display properly and allow zooming to any scale level. When I load the same data in QGIS 1.8.0, the whole-earth layer of boundary lines is not displayed when the scale is low enough that part of the layer is outside of the display. Also, if the layer is visible and I pan the view so that the layer falls part way out-of-view the whole layer is not displayed. This same issue occurs in Fedora 17 standard package and in Windows 7 latest release installer.

test.sqlite - The layer which is not drawn at low scales (1.57 MB) Brian Sipos, 2013-06-17 06:42 AM

shp.zip (1.37 MB) Giovanni Manghi, 2014-06-23 03:17 AM

History

#1 Updated by Giovanni Manghi almost 7 years ago

  • Status changed from Open to Feedback

Does this happens on QGIS master? please try and report back. cheers.

#2 Updated by Brian Sipos almost 7 years ago

Yes, I just installed QGIS master code rev. 28efcda and this issue is present. I free-hand drew some arbitrary layer with similar extents to the one being hidden and see no issue with the hand-draw lines disappearing. The being-hidden layer was created with current version of GDAL library from line data. It's relative large in size (1.5 MiB) but I can send the shape files if needed to diagnose this.

#3 Updated by Giovanni Manghi almost 7 years ago

Brian Sipos wrote:

It's relative large in size (1.5 MiB) but I can send the shape files if needed to diagnose this.

please attach it, cheers.

#4 Updated by Brian Sipos almost 7 years ago

Attached is the shape causing issues. I re-encoded as SQLite to keep a single file, but the same drawing issue occurs as the original ESRI shapefile layer. One issue I know with the layer is that some points are outside of the proper map area (i.e. do not transform to original WGS84 coordinates) but it should still draw consistently at all scales.

#5 Updated by Giovanni Manghi almost 7 years ago

Brian Sipos wrote:

Attached is the shape causing issues. I re-encoded as SQLite to keep a single file, but the same drawing issue occurs as the original ESRI shapefile layer. One issue I know with the layer is that some points are outside of the proper map area (i.e. do not transform to original WGS84 coordinates) but it should still draw consistently at all scales.

your vector seems to have the following custom projection

+proj=cea +lon_0=90 +lat_ts=30 +x_0=0 +y_0=0 +ellps=WGS84 +units=m +no_defs

is this right?

what projection is?

#6 Updated by Brian Sipos almost 7 years ago

Yes that is the correct projection. It is cylindrical equal-area with a non-standard reference location (E90 N30).

#7 Updated by Giovanni Manghi almost 7 years ago

  • Subject changed from Large layer not rendered a low scales to layer with cylindrical equal-area projection does not render correctly

#8 Updated by Jürgen Fischer almost 6 years ago

  • Category set to Map Canvas

#9 Updated by Jürgen Fischer almost 6 years ago

  • Category changed from Map Canvas to Projection Support

#10 Updated by Giovanni Manghi almost 6 years ago

  • Operating System deleted (Fedora, Windows)
  • File shp.zip added
  • Status changed from Feedback to Open
  • OS version deleted (Fedora 17, Windows 7)
  • Affected QGIS version changed from 1.8.0 to master

#11 Updated by Giovanni Manghi about 3 years ago

  • Easy fix? set to No
  • Regression? set to No

#12 Updated by Giovanni Manghi about 1 year ago

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

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