Questions tagged [rendering]
The process of generating an image from a model.
370
questions
41
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12
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How would I draw and visualize custom maps based on OSM data?
I would like to be able to use openstreetmap data for a specific region as a source and "draw" from that the map of infrastructure improvements - mostly roads.
I want it to be self-hosted (not ...
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36
votes
5
answers
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views
Is there a way to render lines with a smooth (bezier) curves in QGIS?
I am moving from creating maps with Illustrator to making them with QGIS and actual data. One of the things I haven't been able to re-create in QGIS are the smooth curved lines I can get in ...
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31
votes
5
answers
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Changing feature draw order in QGIS
Probably a very basic question here, I want to change the draw order of a shapefile in QGIS, how can this be done?
As you can see in the picture below, only the "10" layer is shown, the others are ...
23
votes
1
answer
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QGIS 3.0 point cluster renderer, is it possible to control rendering order (z-order)?
I've been having a play with the new point cluster renderer in QGIS 3.0.2 and it's great - a lot easier (and faster) than having to do the clustering yourself.
To show what I mean, here's an example ...
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22
votes
4
answers
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Optimal video cards for GIS programs [closed]
I recently purchased a Dell XPS-8300 (i7-2600|16 GB DDR3 RAM|64-bit Windows7) which I intend to use primarily for GIS programs. I bought a refurbished model because it was much cheaper and because I ...
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18
votes
9
answers
23k
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Shapefile layers in QGIS don't display unless I zoom out
I have two shapefile layers in a QGIS project that have problems with zooming. One is a line I copied/pasted in a new layer from a set of height contours and the other one is a polygon layer I created ...
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16
votes
2
answers
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How to filter features in a layer?
I am trying to display certain features in a shapefile-based layer using QGIS. I have found the subset function in the properties panel, which does exactly what i want, but is too tedious given that I ...
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15
votes
1
answer
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Wait for canvas to finish rendering before saving image
I am attempting to write a script that will save a rendering of several layers using the map composer. The problem I am encountering is that the script saves before qgis has finished rendering all ...
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13
votes
2
answers
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Is there any option in QGIS to draw parallel lines that snap on the outside part of the line (adjacent lines) that are independent from scale?
I have to draw a map of a public bus transport network and i have a problem in the avenues where a lot of lines passes by.
My objective is to make a visual map where the lines in those avenues are ...
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11
votes
4
answers
10k
views
QGIS rendering performance bottleneck?
When I load a vector with a large number of features into QGIS, the rendering time can become extremely slow. But when I look at my system resources, they all have plenty of excess capacity.
What is ...
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10
votes
2
answers
750
views
Setting data-driven symbol levels in QGIS
How to drive symbol levels based on an attribute or data element such as area in a QGIS layer? How to set data-driven rendering order?
We have a set of boundaries that include very large and very ...
10
votes
1
answer
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Does the projection of a PostGIS table affect the rendering speed in QGIS?
I am interested to know whether changing the projection of a PostGIS table will affect the rending speed when viewing it in QGIS.
I have two layers coming from QGIS which are exactly the same and ...
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votes
2
answers
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Can Mapnik render spatial data from SQL Server?
This is a very simple question - I just want to know if anybody can confirm that they have successfully used Mapnik to render tiles directly from data held in SQL Server. (And, if so, what did you do ...
9
votes
4
answers
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How Can I Make QGIS Stop Blinking Every Time I Pan?
The way QGIS draws the canvas when panning is quite annoying. If I pan the map even a little bit everything goes blank for a second or two before the layers are drawn. It looks like this happens only ...
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8
votes
4
answers
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Fastest spatial storage format?
I am wondering what storage method will result in the fastest reading of the map vectors for rendering. SHP? PostGres? SQLite? (They do not change often and I do not need spatial functions for these ...
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8
votes
1
answer
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Layer not repainting using PyQGIS
I'm trying to change the color ramp for a raster layer using PyQGIS.
What I have works, but the layer doesn't redraw. However, if I open the layer properties and click "Apply", the map ...
- 279
8
votes
2
answers
1k
views
Maps, black and white/ gray scale printing
I'm working on Mapserver to do beautiful maps with AGG rendering
Until now, I've only thought about the best way to get color maps. Now, I have to think how to make color ones compatible with a grey ...
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8
votes
2
answers
4k
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How do I rotate the OSM map before printing?
What is the simplest way to rotate and render Openstreetmap data, and still get a nice render? For example Toronto, would fit best rotated slightly on a page in landscape mode, so the northern ...
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8
votes
1
answer
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How to Optimize Openstreetmap Tile Rendering?
I am currently trying to render Water (3,198,333 records) and detailed world borders (processed_p) for the world. I am successful in rendering both layers, but I am not happy with performance.
My ...
user5584
7
votes
2
answers
1k
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How to render Multi-Response GeoJSON tiles
I am using TileStache to combine and server multiple vector layers in a single Mutli-Response GeoJSON tile, which is basically all my individual tiles/layers (GeoJSONs containing either roads, pois, ...
- 3,328
7
votes
1
answer
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Saving Map Canvas as PNG with transparent background programmatically with QGIS?
I wrote a script to create a big number of heat maps for a given scenario. I would like to save the result of every heat map as an PNG image. I have figured it out doing it with simple Map Rendering ...
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7
votes
1
answer
427
views
How to keep polygons detailed when exporting in QGIS?
When i export to pdf from QGIS the polygons become rounded or bloated. This image is a printscreen from the workspace in QGIS:
This image is a printscreen from the pdf (size A3 zoomed in 800%):
...
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7
votes
3
answers
492
views
How to handle display of nested polygons (census, county/state, etc) for a given map extent
My question is how best to decide which layer (from a set of nested, aggregated census polygons) to display for any given map extent in an online map.
Australia's census boundaries are built from ...
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7
votes
2
answers
2k
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Leaflet: How to enable pan & zoom while GeoJSON still rendering?
I've overlaid a huge GeoJSON geometry on top of my Leaflet map, covering about 20 countries' borderlines (about 1,5 million vertices) using "L.geoJson".
Each time I zoom in/out, the computer has to ...
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6
votes
3
answers
6k
views
Inverted filling of polygon in QGIS
Is there a way to color on the outside of polygons like this?
I have tried to use the inverted polygon style in QGIS but it didn't work.
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6
votes
2
answers
738
views
Applying HDR (high dynamic range) rendering in QGIS
I want to automatically (without manual adjustments) apply HDR (high dynamic range) rendering to Sentinel-2 satellite images so that the image can distinguish between very bright objects (e.g. clouds, ...
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6
votes
3
answers
4k
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Obtaining *rendered* OSM data
I'd like to produce a simple walking map with some points of interest. Ideally, I'd like to use the rendered OSM data, as you can get from the page. Using the QGIS OSM plugin, I can only download a ...
- 3,332
6
votes
1
answer
141
views
Contrast enhancement on UInt16 data type to set the maximum value greater than 255 with PyQGIS
I have loaded a raster layer with gdal DAAS plugin and would like to set a contrast-enhanced rendering, but my pixel data are in the range [536, 1747] and I cannot achieve modifying the max value of ...
- 163
6
votes
3
answers
2k
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Render the PostGIS OSM data in 3d?
I wonder is there any open-source application that can query a PostGIS-enabled database and render the resulting OSM map in 3d.
The only thing I have found so far is Navit, but it renders only from ...
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6
votes
2
answers
601
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How to render bottom layers after higher ones in QGIS?
I'm using QGIS 2.14.3.
Is it possible to render bottom layers after higher layers while still keeping them underneath? (or can rendering only be bottom-up?)
I have seen the "control rendering order" ...
- 1,852
6
votes
1
answer
418
views
Configure symbol levels using PyQGIS
I have a QgsCategorizedSymbolRenderer and I'm trying to configure it so that symbol_a:
appears at the top of the layers window legend, but also
appears on top of all other QgsRendererCategory symbols ...
- 469
6
votes
2
answers
579
views
2D export renderer creating anomalies using ArcScene
A lot have been improved in the 3D Analyst 10 including the ability to export large scenes as large 2D images. However, some problems still exist one of which is:
When I export a scene that contains a ...
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6
votes
3
answers
1k
views
Creating a Vector Tile base map
I want to create a vector tile base map using my own shapefiles/postgis tables for use on a mobile primarily. By my understanding the process is divided into 3 main steps:
Creating/slicing the data ...
- 3,328
6
votes
0
answers
368
views
Applying graduated symbol renderer only on some features using PyQGIS
I have set up a graduate symbol renderer (QGIS cookbook - Graduated Symbol Renderer), and I am now trying to make it conditionally applied to some features only, depending on one (or more) attributes. ...
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6
votes
1
answer
1k
views
Map on canvas renders after image saving [duplicate]
I'm a beginner to Qgis and Python;
i need a script (don't need it to be a plugin) to get maps of selected features from a layer satisfying certain conditions;
Here is my code:
from qgis.gui import *
...
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6
votes
1
answer
734
views
Can you set a QGIS print composer to render the map as default?
I have set up a number of templates for the print composer in QGIS.
In the Print Composer, there is the option to have the map image displayed in 3 ways:
as a blank rectangle with no updates until ...
- 370
5
votes
8
answers
2k
views
Any Good Map Rendering Engines for SqlGeometry/SqlGeography
Can anyone suggest good map rendering engines for MS SQL Server Spatial types (SqlGeometry/SqlGeography)? By rendering, I mean plot the geometries to a common image format such as png or jpeg with ...
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votes
2
answers
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How can I display this polygon in Google Maps, properly
NOTE: this question is sorta like a follow-on question to this original GIS Question I asked. In that question, the main suggestion was that I was trying to show two polys. Now, I'm asking about a ...
- 1,793
5
votes
2
answers
9k
views
How to make the white background of an RGB raster transparent?
I would like to show on my map only the reddish pixels of my raster layer.
Said in another way: I would like to transform my white background into transparent background so I can see my other ...
- 1,154
5
votes
2
answers
378
views
QGIS renders outlines where none should be
QGIS always renders the borders of a feature polygon. How can I disable this?
Even if I set Border style to "No Pen" and the colour is exactly the same for different categories there is a small grey ...
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5
votes
1
answer
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Blending features in QGIS: Approximating road edges for map render
I'm having trouble getting the right render for the tertiary roads and service roads look in my map render. I'm trying to get road edges like in the old USGS topo maps:
Notice how the road interior ...
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5
votes
1
answer
147
views
Labels displaying with multiple bounding rectangles
While setting up labeling of a line (road) layer, the labels started displaying with multiple bounding rectangles along with the text.
After trying many different labeling configurations without ...
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5
votes
2
answers
263
views
Why QGIS crashes when constructing QgsGraduatedSymbolRenderer object by QgsGraduatedSymbolRenderer.createRenderer() method?
Today I want to render a vector layer in QGIS by using PyQGIS QgsGraduatedSymbolRenderer renderer. When I directly construct it by using the constructor, it works. But when I want to use the ...
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5
votes
1
answer
631
views
How to suppress polygon boundaries shared by objects of same type in QGIS?
Given polygons - like landcover in OpenStreetMap or street areas in cadastre - how can one suppress those polygon boundaries which are shared by objects (features) of same type in QGIS (see figure ...
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votes
1
answer
165
views
Set fixed reference scale for QGIS layer with PyQGIS?
Is it possible to set a fixed reference scale for a QGIS layer using PyQGIS?
I try this script but it doesn't work:
lyr = iface.activeLayer()
r = QgsFeatureRenderer()
r.setReferenceScale(400_000)
...
- 1,047
5
votes
1
answer
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In QGIS, how to control the rendering order of objects in a single layer with rule-based symbology?
In QGIS 2.18, I have a symbology of points in a layer based on rules.
I want to control the rendering order of the layer in QGIS, with on top the type with the lower counts.
Intuitively I would ...
5
votes
1
answer
2k
views
Dynamically move map canvas and main window using PyQGIS
I am trying to create plugin that will open new window with some layer, Dynamically "pan" my window, when main window is pan. So boundingbox coordinates should be the same in both windows.
I need new ...
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5
votes
2
answers
831
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How to render layer into png in a standalone application?
I would like to use standalone appliction to apply .qml style to a layer and use QgsMapRenderer() to save it as image on a hard disk. The are a lot of questions like mine at this site and it seems ...
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5
votes
1
answer
4k
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Labels appear and disappear for no apparent reason using QGIS?
I'm going through the Alaska sample data tutorial for QGIS 2.2.0. Some of the lake labels appear and disappear at different scales when zooming. At 1:314,460 Becharof is visible, but Lower Ugashik ...
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votes
2
answers
387
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Why is QGIS only one label rendering at a time?
I'm new to QGIS, but I'm experiencing what I think is a bug.
When I load the qgis_sample_data landcover raster and lakes vector layers, then enable labels for NAMES on that layer, I can only ever ...
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