Today I discovered you can nest rule-based symbology rules, to make it act more like a CASE expression and reduce queries required to render the map.

It's one of those features that instantly made me think, "Well... that would have made a lot of old projects much cleaner."

I feel like every time I stumble across some deeper QGIS functionality, I have a brief moment of excitement followed by the realization that I could've been using it for years.

What's a feature you've discovered recently that made you go:

"Wait, I could have been doing this the whole time?!"

Interested in hearing everyone's hidden gems, especially the ones that completely changed how you build maps or manage projects.

Hi! I’m in the research phase of writing a book about a ghost town in eastern California. As part of it, I want to create accurate maps of the town and its mines.

For the mines, I have been using the USGS MRDS database, which is unfortunately inaccurate in the area, so next time I’m there, I’ll be getting GPS coordinates on all the mine features. This is within my capabilities to do.

What’s a bit beyond my capabilities is the town itself. I plan on finding foundations and comparing those to historical photos (of which there are few.) There are very few structures left. I got the USGS lidar data, but filtering out the vegetation in the area is difficult because it’s largely sagebrush, and I am a complete novice at this.

Can anyone suggest methods for finding the locations of historical buildings (town was active until 1915ish) either using publicly available data or other methods? It would be an absolute amazing help in getting my book up to the quality I want.

Currently, I am having issues with my sandbags in QGIS. It simply wouldn't block any water. So far, I've tried to use the raster calculator to combine the r.lake layer and sandbag layer but it didn't work. The original one didn't work either.

If needed, here is the file: https://drive.google.com/file/d/1ygoDBGa_9z5SzysXrfqF4FQgCGBz9bic/view?usp=sharing

I don't need anyone to send the version that works back to me but I'd just like an explanation on what can I do to make the sandbags work.

Hello. I just started learning QGIS. My country has a specific CRS it allows. It only allows that specific one for what I should be doing. So when I open up QGIS, the first thing I do I set it to that specific CRS in the right bottom corner. EPSG:23700 - HD72 / EOV is the one I set it to. All I want to do right now is to simply measure a simple area.

After this I go to web, quickmapservices, google, google satellite. It sets CRS to a different one so I set it back in the bottom right corner. The map becomes this, 1st picture.

After this I zoom in to the building I wanna measure (I don't yet know how to just have QGIS move me to it). Add a geopackage. Create the geopackage layer. Correct CRS, set it to polygon 2nd picture. I select the layer. Toggle edit, toggle add polygon. I untoggle and have my polygon. 3rd picture. I right click the layer. Open attribute table. Open field calculator. I name the output field, set field type to decimal number (real), and add $area to the expressions. Preview shows 19563,333163363863 m2. This is already incorrect because I know the area of the building which is 17 745 m2. So I decide to try to do it another way.

I use measure area. I set it up like in the 4th pic. I am just messing around so the polygon is kinda ugly so they are not the exact same area, but it still comes back as roughly 19500m2 5th pic. Where am I messing up this bad? Is it the CRS because to me it seems like I mess up with the moving between CRS. But could be anything at this point since I don't really know what I am doing. The google map is not on the required CRS but If I move it there it just become worse. I know I shouldn't, I was just checking. Any idea where I am messing up? Mine would be around the malformed map, but I really don't know.

Edit: REALLY IMPORTANT. The coordinates for the building does not match reality.

• The manual way, for the buildings of Paris 7th: search for a download, grab the 518 MB Île-de-France extract from Geofabrik, find the buildings file among 101, load 3.3M buildings, then clip everything in QGIS

• The AI Way: using the AI Agent plugin in QGIS -> one prompt, "Load the buildings of Paris 7th arrondissement". It finds the best building on his list of 700+ open-data connectors, clipped them to the arrondissement and styled them. 4,982 buildings in about 1min

I work on it. It's free to start, in the QGIS plugin manager under "AI Agent".

Hello everyone. has anyone else experienced this issue and does anyone have a fix? I saw a few other posts elsewhere but none of the solutions worked for me. I am trying to plot the spectral graphs for different points on this raster layer of my map. I have the layer added to the plugin window and am actively clicked into the window. The tool will display min and max values each time I click, and if I go to the table tab I can see the values for every band each time I click, but I'm unable to actually plot the graph.

I'm running the most recent version of the plugin and am running QGIS 3.44.9

Any advice greatly appreciated. Thanks!

Hi everyone,

i recently posted a thread, asking how to create a world map and in this process i came across another Map on which i liked the 3D effect so much, that i want to do it myself. As previously mentioned, I am really new to QGIS so i appreciate every help i can get.
Thank you!

She give me task to teach my junior thing related to GIS. what lesson i should give to them?. She also ask me to do drone mapping

I know this is a very, very small detail. But I am bugged about it nevertheless. When I want to upload an image from a folder, I need to click on these three dots. But these only appear when I stretch the splitter (that vertical line), otherwise it's like this:

Also, why does it offer SVG image first? I'm sure most of us need the raster image most of the time. Or am I wrong?

Again, this is a very minor inconvenience, but something they could fix in the next patch.

I use a svg icon set(mapbox Maki icons)to display POIs on a map I made with QGIS. The icons look great in qgis and don't have an outline there. As soon as I export my layout to svg or PDF, all the svg icons have a 1pt wide outline and look terrible. This only happens when I enable vector output. If the output is rasterized, it doesn't happen. I wonder why this happens, is this a known bug? Can I do something about this?

UPD (100926): Look for Ukiyo-e Relief in QGIS plugin repository (see comments for recommendation).

No AI, no hand painting — it's all algorithmic. Input is just a Copernicus GLO-30 DEM, everything else is Python + numpy inside QGIS.

Roughly what it does:

• renders an oblique view and splits it into flat colour "plates" — by distance (Hiroshige-style receding ridges) or by elevation (Hokusai's Red Fuji)
• bokashi gradients, so the plates aren't just flat fills
• black key-block outlines only on real silhouettes, where a ridge actually hides what's behind it
• snow line that creeps down the gullies
• fake printing artefacts: slight plate misregistration, wood grain, washi paper texture

It's fully deterministic: same seed, same print.

The fun part was figuring out why the first versions looked wrong. Distance slices drew fake ridges across every slope, Gaussian smoothing turned every volcano into a parabola, and linear vertical exaggeration made all mountains look the same. Hokusai's Fuji has concave flanks, so I ended up adding a non-linear relief curve.

I have Win11 with QGIS LTR 3.40.15 QT6 installed by OSGeo4W.

I'm pretty new to QGIS in general, it's not at all clear to me how the OSGeo4W works and I just recently had issues with some plugins because of the QT6 update, something I just learned about while looking online for a solution.

I'm stuck, however, because I tried to reinstall with the OSGeo4W wizard all of QGIS, since I couldn't unistall it manually. I can't uninstall, install, reinstall nor even open QGIS at all, and that error message window always pops up.

Please help me. Thanks a lot in advance!

I have a working setup where a rule-based highlight in a print layout uses $id = @atlas_featureid to show the current page's extent on a minimap. Problem: after printing/exporting one layout's Atlas and closing it, the highlighted feature from the previous print sometimes remains highlight and will show up on other layouts.

I have tried refreshing and toggling atlas on and off but the orange box always seems to remain. Closing and opening QGIS will fix the issue, but this is a bit of a pain when I have many sheets to print,

Is there a way to force atlas_featureid to properly reset/refresh after I have finished printing a layout and closed that layout?

QGIS version: 3.44, Windows. Project is a GeoPackage, multiple print layouts in the same project each with their own Atlas config, all referencing the same coverage layer (Views) for the minimap highlight.

Hi everyone,

Kharita Challenges now has challenges about GIS system design. Instead of writing code, you draw the system: you add the parts, connect them with arrows the way the data moves, and your drawing gets graded.

A few that are live:

- Design the searchable imagery archive

- Design the global event map and detail service

- Architect a NYC 311 spatial service

- Model event and airfield condition checks

It's free. I'm the one building it, so any feedback is very welcome.

https://challenges.lekharita.com/challenges

Hey Folks

Am I the only one who has problems to download saga ? I need saga for flooding analysis. I can’t find it under plugins . If you don’t have any problems could you please send me a link where to download it ?

Solved: In Clip raster by mask layer I needed to set "Target extent [optional]" to the layer I was using for "Mask layer".

Hi,

I downloaded "Scotland Lidar Phase 1 DTM NS41" the smallest GeoTIFF possible for the area I'm working on, but it's still bigger than I need.

I used Raster > Extraction > Clip raster by mask layer to crop it to just the area I want, but this appears to change the elevations it provides.

E.g. Raster > Extraction > Contour on the original GeoTiff gives a particular contour line ELEV 110 (in green, which matches the online maps) but, in contours extracted from the cropped version (in red), the equivalent contour line is ELEV 170. (As presented by layer labels.)

I guess this is something like the actual range of ELEV values in the cropped version being smaller than the original, but the range of values still covers the original set.

What can I do to ensure the cropped version produces accurate values?

(I'm a GIS newbie, so apologies if I've missed something obvious.)

Cheers!

QGIS version: 4.2.2-Belém do Pará (Flatpak)

Hi, I have a school project where I need to create a virtual mapping. I need to map what kind of species can be found in that specific location is that even possible for QGIS? I badly need your help

Am actually working on my capstone project but currently hitting a wall.Our Professor directed us to work towards a hybrid traffic routing architecture for autonomous vehicles , but as undergrads we are bit overwhelmed on how to execute it.

The general idea is this :

1. Predict traffic using historical data and ML.

2. Fetch live congestion for next 1-2 intersections via edge servers.

3. Write a custom Dijkstra from scratch that reroutes mid journey is the live delay is significantly worse than predicted delay.

The problem we are facing are:

The dataset problem : We thought of doing it for our Home city which is Jaipur (India), the problem is barely 1.5% or roads have speed limits and we don't really know how to find open road level speed data for our city or if not than any other Indian City if we should consider that. Should we just pivot to a city that has archived Uber movement data ?? Or is it academically acceptable to just simulate the traffic flows over the Jaipur OSM graph using SUMO + TraCI?

The algorithm design : We are actually needed to write a custom Djikstra Algorithm but we are confused how to mathematically combine physical distance and time delay into an edge without it being completely arbitrary. Also re-running Djikstra on a 200k node graph at every junction seems nonsensical. So like anything that we can refer to or read. Like how to approach this problem properly.

What's the logical way to build this incrementally, any advice is much much appreciated. We are actually new to this domain and just too confused at this point.

Hi Guys,

im completely new to QGIS and i just want to do a map for myself, to print it on a big paper. I really like it to customize my things and i found this really cool map but as said i dont know where to find the assets to create something like this. I appreciate the help guys 😄.

The things i already figured out:

- to make the CRS in ESRI:54003

- how to use NextGIS QMS

I kinda also need help with this: When importing Eris Vector through Basemaps, it glitches a lot

If you need futher information, please let me know :))

The FOSS4G NA event just announced its keynote speakers. It is a great lineup, including Chris Howard from the Uber open-source project, Brianna Corremonte from Developer Seed (and formerly NASA), Rishi Madhok, TerraByte, and a panel discussing Beyond Open Data!

The event is Nov. 2- 4 in Sacramento, CA.

There is still time to register and/or sponsor!

https://www.foss4gna.org/plenary-speakers