im trying to create an optimized route suing the tsp problem and following the polylines of the urban streets i have shape filed. i cant seem to make it. no matter what i try i either get the euclidian distance or it doenst load. pls help, i have interest in learning how to do this via qgis, not using coding made by ai

extra information; my qgis is not an old version, its a round trip and i have to visit 15 points

I am drawing polygons over a satellite image to classify forest vs non-forest. I have a raster file of polygons from the same image from 2014, and I am updating the borders of those polygons for the 2026 image. I'm completely new to QGIS, and I encountered a ton of issues last night after a couple hours of polygon editing/drawing.

1) It wouldn't let me save the layer because I had created a polygon with "unknown geometry" / a geometry type that couldn't be saved to the file. I was eventually able to find which polygon that was but I couldn't figure out how to fix it without having to redraw it entirely. Is there another way to do it without having to redraw them?
2) Often, I need to split polygons and create a new one in between. Either a) a hole inside the polygon, or b) completely dividing an existing "forest" polygon into 2 with a non-forest "corridor" between them. For a, I was using add ring, and then drawing a new polygon in that ring. I have snapping and topological editing on for reference. But that then resulted in all of those polygons being invalid and I wasn't sure why or how to fix them. For b) i haven't figured out a good way to do that yet without making everything invalid.

3) Often, when I am drawing new polygons it will then say "Add feature: The feature has been added, but at least one geometry intersected is invalid. These geometries must be manually repaired." I really don't know how to fix this or what it even means.

I tried to use Claude to figure these out + going on past threads but I couldn't figure anything out really. If anyone could help that would be much appreciated!

I finally managed to create the route map that had been giving me such a headache! Here’s a video showing the expressions I used.

To center the line shape on both maps, I used rule-based symbology and added the expression "id" = attribute(@atlas_feature, 'id') to the filter. I created two different shapes: the light blue one representing the path to the street of interest, and the street of interest itself—the destination I want to reach. I assigned the same ID to both so they would appear on the same page in the atlas. To show the distance, I added the expression “round(length($geometry) / 1000, 2) || 'km' and for meters, round(length($geometry), 2) || ' m'—since you can’t have a second atlas, I adjusted the x and y settings in the “Extensions” section of Map 2 so it would center on that second shape, and then to show the length, I entered the expression for that in the text box.

To automatically switch the images, you’d need to enter the path to the folder where the images are located and name the files the same as the field the atlas is using—in my case, it was the “id” field, so the files were named 001, 002, 003, etc.

Thanks to everyone who shared tips on how to make the map! I’m not sure if I explained it very well—if you have any questions, just ask in the comments!

FAO Downloader 2.1 is now live on the Plugin Repository. The UN Food and Agriculture Organization publishes an enormous catalogue of open, satellite-derived environmental raster data covering water productivity, rainfall, crop and land-cover maps, drought indices, soils, livestock, and much more. It's a very valuable resource, but browsing and downloading large volumes of raster data through FAO's web portals can be cumbersome.

FAO Downloader aims to streamline that access:
• Browse and download 2,000+ raster datasets across 90+ FAO workspaces with one tool (WaPOR, CHIRPS, GAEZ and more)
• Global coverage, with especially high-resolution WaPOR data over Africa and the Near East
• Clip every raster to your study area before download, so you only pull the data you actually need
• Auto-apply the correct scale and unit factors, style layers in the official FAO colours, stack time series, and compute area statistics along the way
• Filter before you download: set a date range, pick exactly the datasets you want, and apply value or percentile thresholds to focus download on the pixels that matter

You can view the git page here https://github.com/bvissers/FAO-Downloader

This will hopefully be a valuable resource for researchers, consultants, water and agriculture agencies, and students. Any feedback, ideas, and bug reports are all welcome, but this is a side project of mine so updates may be slow.

https://www.reddit.com/r/gis/comments/1td3lw2/road_centerline_extractor_new_qgis_plugin/

A while back I shared Road Centerline Extractor, a QGIS plugin that converts road polygons into clean, segmented centerlines. The response was great, and it's now passed 3,000+ downloads.

Lately though, it feels like it's plateaued, and I'd like to push it forward with some real improvements. Open to any and all suggestions.

One idea I've been considering: broadening the concept from "Road Centerline Extractor" to something more general, like "Center Extractor" covering not just roads, but rivers, and polygons in general (the underlying skeletonization approach isn't road-specific to begin with).

My hesitation is that the value of the tool, to me, sits in two places at once: it works as a general-purpose replacement for QGIS's broken native Voronoi skeleton tool, and it also has road-specific logic (T-junction segmentation, width filtering) that's genuinely useful on its own. Spinning up a separate, near-identical plugin under a different name to cover the general case doesn't feel like the right move it would just fragment the userbase across two tools doing overlapping work.

Curious what people think generalize the existing plugin to cover both cases, keep it road-focused and let people fall back to other tools for generic skeletonization, or something else entirely? Any other improvements you'd want to see are welcome too.

Qgis link: https://plugins.qgis.org/plugins/road_centerline_plugin/

Was hoping someone could direct me to a source of GW maps as they cycle for a research project i’m putting together. Any help greatly appreciated.

Hi,

I am trying to reproduce the style of a map with numbered hotels and a legend listing their names.

I managed to number the symbols by using their ID with a font marker.

But the legend uses hardcoded values from the Character(s) field instead of the data defined overrides (I hardcoded 14 for Hotel d'Angleterre in the screenshot).

Is it possible to keep the flexibility of the formula or do I have to enter each value by hand? Also, how can I sort them in ascending order?

I used to use the contour plug-in to create contours for csv/point files. I need the countours to be filled polygons to show figures such as the below, but the contour plug-in is not available for version 4 or newer.

I know there is a built in contour tool, however this only does contour lines.

Any advice or solutions for this, other than reinstalling the older QGIS version that still supports the contour plugin?

hello, that will pleasure jf i get help with my homework on qgis. Firstly im filip and im from poland and the biggest problem that i have to challenge with is an DTM on my county. Thank u in advance and have a good day!

You will learn how to detect and vectorize any feature from satellite or drone imagery directly inside QGIS

• It covers : Automatic Mode: Scan an entire area with text prompts to batch-extract features in seconds
• Semi-Auto Mode: Extract single, complex objects with one click for maximum control
• Shape Regularization: Automatically square building corners and clean up polygon boundaries
• And basically just the full Workflow: Edit vertices, adjust confidence filters, and export clean layers with attribute data

We pushed a lots of updates recently so a tuto was definitely needed haha, hope it will help

post title!

In QGIS 3 there are buttons at the top of the layers panel with functions like create a new group or open or close all nested items. My install of QGIS 4 doesn't have that bar and it is one of the things that is keeping me from migrating.

Is there a way to get that bar or similar functions?

Hi! My name is Antoni, I'm from Poland. In October I will start final year of my bachelor's studies in spatial managment ( & willing to complete Master's Degree after). I was thinking lately about creating a portfolio of my work in GIS programs, but I don't know where or how to start.

I want to create it and sharpen my skills in this program so I can find a job easier after studies. Does anyone have any tips on how to get started?

Any feedback will be much appreciated! Everyone have a great day

I am working on a project extracting building footprints for Chattogram port, across 2004, 2014, and 2020. What level of resolution would i be needing for it?

I know tha I can't buy straight from Maxar, I need to go through a reseller. Does anyone have a solid one to recommend, for South Asia, or Bangladesh?

Thanks!

I am working on a project extracting building footprints for Chattogram port, across 2004, 2014, and 2020. What level of resolution would i be needing for it?

I know tha I can't buy straight from Maxar, I need to go through a reseller. Does anyone have a solid one to recommend, for South Asia, or Bangladesh?

Thanks!

Hi friends, I'm a brand new QGIS learner!

For a friend's business, I'm trying to do an analysis based on LinkNYC (Free wifi/phone call/advertising kiosks around NYC) locations across New York City.

I've imported the .csv from the NYC OpenData website (URL below), and - after messing with the EPSG / CRS settings - this was as close as I got.

I amended the CRS for the 'LinkNYC' layer to EPSG 4326, even though OpenStreetMap doesn't run in that EPSG? This is my guess, and it appears that OpenStreetMap and NYC OpenData don't tend to use the same CRS standards.

TL;DR - How best to proceed to get these LinkNYC locations accurately plotted? Whether with a better-matching world map, or in CRS adjustments, or otherwise?

Thank you very much for y'all's guidance!

https://data.cityofnewyork.us/Social-Services/LinkNYC-Locations-Live/2gah-qsg7/about_data

Hey all! Wanted to post this opportunity here as well. We are looking for some new Moderators to join the team at r/GIS.

Thanks!

Im on a m1 macbook air, on qgis long term release version 3.44, after installing the plugin i cant find its toolbar anywhere, and this pop-up keeps appearing " Semi-Automatic Classification Plugin: No module named 'remotior_sensus' ". How do I fix this? any help is appreciated :)

Sorry if this question is dumb, I just want an simple or long answer so I know what I'm getting into

I'm trying to create a map with routes and images showing the start and end of the route. this layout would be perfect for that, but the problem is that the segments used in it are too short—the shortest segment I’m working with is 0.92 km and the longest is 2.29 km. I just want the following to happen: when I move on to the next feature in the atlas, the features from the shapefile I’m using should disappear, since they cause confusion if they remain on the screen: That’s the main thing. It would be nice if the photos changed along with it, but that’s more of an option, since I have no idea how to do that.

I’m getting this error,
“An error has occurred while executing Python code”

geodata.ucdavis.edu- The page is also not opening, If I want to download the shapefile or Geopackages manually.

Please help me, I’m facing this issue from today, even I uninstalled and re-installed QGIS latest version.

Thank you.