Bug report #14855

Strange result when hillshading with Z-factor=10 in the "Terrain Analysis" core plugin

Added by Lene Fischer over 8 years ago. Updated almost 6 years ago.

Status:Closed
Priority:Normal
Assignee:-
Category:Analysis library
Affected QGIS version:2.14.2 Regression?:No
Operating System: Easy fix?:No
Pull Request or Patch supplied:No Resolution:worksforme
Crashes QGIS or corrupts data:No Copied to github as #:22808

Description

I create a Hillsade from Raster>Terrain analysis>Hillshade.
Using parameter Z-factor 10
Azimuth 315
Vertical angle 45
I get a grey/dull/flatten image
If I change the Z-factor to 1. I get the same result, just a bit lighter color.

Using the same function from Processing>GDAL I get a 'useful' image

hillshade10_GDAL.JPG (245 KB) Lene Fischer, 2016-05-22 02:48 AM

hillshade10_core.JPG (49.7 KB) Lene Fischer, 2016-05-22 02:48 AM

History

#1 Updated by Giovanni Manghi over 8 years ago

  • Category changed from Rasters to 119
  • Priority changed from High to Normal

Hi Lene, could you attach sample data to allow replicate here? thanks!

#2 Updated by Saber Razmjooei over 8 years ago

  • Status changed from Open to Feedback

Lene,

Is your Z value in the same unit as your x and y. For example, this happens if you try to scale lat/long raster rasters.

#3 Updated by Lene Fischer over 8 years ago

Yes same value.
Utm 32 N EPSG 25832 for x,y and meter for Z-coordinate.
The files are to big to attach here. I try to upload to my webpage and insert a link here later.

#4 Updated by Lene Fischer over 8 years ago

Link to data http://ku-gis.dk/blog/wp-content/uploads/2016/05/dtm_1km_6183_693.zip

I have the same issue for single files.

#5 Updated by Giovanni Manghi over 8 years ago

Lene Fischer wrote:

Link to data http://ku-gis.dk/blog/wp-content/uploads/2016/05/dtm_1km_6183_693.zip

I have the same issue for single files.

I guess this is sample data about the ticket for raster min/max values (#14835) and not this one, correct?

#6 Updated by Lene Fischer over 8 years ago

I use the same data for both tickets.

#7 Updated by Giovanni Manghi over 8 years ago

Lene Fischer wrote:

I use the same data for both tickets.

what is the file you used to hillshade and that gave you the results you attached as jpg in the original description?

#8 Updated by Lene Fischer over 8 years ago

From the the files in the link I made a VRT file.
You can also use just a single file.

#9 Updated by Giovanni Manghi over 8 years ago

  • Subject changed from Hillshade - Z values load to Strange result when hillshading with Z-factor=10 in the "Terrain Analysis" core plugin
  • Status changed from Feedback to Open

#10 Updated by Giovanni Manghi almost 8 years ago

  • Category changed from 119 to Analysis library

#11 Updated by Giovanni Manghi almost 8 years ago

  • Target version changed from Version 2.14 to Version 3.0

#12 Updated by Giovanni Manghi over 7 years ago

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

#13 Updated by Alexander Bruy almost 6 years ago

  • Status changed from Open to Feedback
  • Description updated (diff)
  • Operating System deleted (Windows 64 bit)

Just tested with master and got correct results. Can you test again?

#14 Updated by Alexander Bruy almost 6 years ago

  • Status changed from Feedback to Closed
  • Resolution set to worksforme

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