QGIS Freestyle!

okay great and we are live i'd like to welcome everyone to the last session of the day this is going to be a really sort of fun and interactive session so i'm really really keen let's hope that i can stream and use qgis at the same time without my computer crashing so i will just hand over to tim who's going to take us through to our hugest 3d freestyle session woohoo okay thank you amy and hello everybody um this is a like an interactive session where you all invited to participate so we've got a panel of qgis nodes present in the room but just because we're the side of the camera doesn't mean you can't also just participate with us and and basically the format is that we're going to give everybody a data set the same data set ideally that we've generated using this gen a random dem generator and then you can take the the dem and do whatever you like that the only like preconditions are that you can't bring in existing data so you've got to create everything from scratch from the dem or you can digitize points or lines or whatever on top of it or you can produce new products using whatever means you want to and analysis tools or you know python whatever you want to do but you can't use something that you've already got like lying on your desk okay and at the end of it the idea is that you produce a picture or a layout or a map or something that's visual and that we will share them on the github repo that i've made um and then we'll have some kind of um judging panel that will will review the what we've submitted and not just ours but from the community at large and come up with the winner and the winner will get a cue just coffee cup sponsored by cartosa okay and it will be the beautiful black one with the cutest logo and there's a picture of it on the wiki page um so to get started um i'm just going to share my screen and give you some like somehow to find your way to the to the page and we can if you can put it in the chat of youtube as well for us um sorry i'm trying to find the shape [Music] uh so if you go to the heck first uh open day sorry i'm dating myself now the key just open day page um you'll find the talk details for the session um and you'll see that on beneath the coffee cup um i kind of put a link to the freestyle page which should take you to here click it to see where it goes um and there's the same rules which i just explained basically that you can't use pre-existing data and i'm hoping that we can do future sessions i'm making one basically an issue in github for each session so today's session is number one here and and on that session you'll find there's this um this pupil you just opened a den dot zip which is the data set that we all use i haven't looked at it yet either and and when you've when you've created something then just make it as a png or a zip file and then you just drop it in as a comment on this issue okay so amy if you i'll share in the chat if you can share the issue it's the shortest way to get to where we are now you can share that on youtube as well that would be great and um what we'd like to do is just kind of like switch between uh like share your screen alternatively so we can kind of like peak as you as you're building stuff and maybe uh give a little update every few minutes or between between us and the panel here of what you've been making that's it that's it's simple i think i hope if anything not clear just you can tell me and all good damn downloaded link on youtube ready ready start your engines and let's go all right i hope that the name looks alright because it looks like there we go so that's what you're gonna you should you should be starting off with and it's at pixel values and degrees so it's in uh with a wonderful eps g4326 so each pixel is one degree or you can reassign the coordinate reference system it's it's in fantasyland it's nowhere and well i think at this point it might be on another planet me like another planet i could go for the aliens yeah sorry i think i cut you off there uh were you saying something else yeah i was just wondering about the crs i think a lot of the tools going to break if you don't assign a crs or reproject it to something yeah that's a challenge yeah i have a solution without projections that should work i see you've got the python command for using the script to generate new dems tim but it's got some dependencies uh i think on google which is not available in every path and environment yeah but just use you can just use the one in the ticket i mean you should ideally all use the same one no i'm using the same one i'm just saying for people who want to use that that generally yeah it works great under linux that's a good reason to switch to let's just i used condom windows worked well needed numpy okay yeah condo will work well on windows oh tim are you speaking no would you like it i was just wondering if you were because i can't hear anything no i'm deep in thoughts looking at my screen and pondering about my rest a mask polygonization that i'm busy doing we're sort of hoping that those watching if even if you not participate you can and we can switch to the next person's screen in a second that you can kind of learn some cue just tips by watching what people do here somebody's got something interesting to show on their screen you can just shout and then we can swap this screen sharing over i don't know if it's possible to all share screens at the same time it could also be an option i don't know can jitsie do that i think youtube can't handle that because it needs focus on one oh yeah oh yeah that makes a lot of sense but i i've got something to show let me just share the screen i just will stop here go for it all right so i was doing it i think i just want to set up the the base map and then i want to do some analysis and do uh show on top but for the base map what i did was i just assigned a crs to the layer just because some of my analysis tools need natural units so um i just assigned psg 3857 and this is the base 10 uh the first step i did was just did some styling so i had a style map file which i prepared which i commonly use for my dems just a nice color ramp that i designed and this looks like this and then i generated a hill shade uh out of it so this is the hill shade and uh what i want to show is this uh trick i learned actually from third monkey a while back and i still use it is if i want to do a colorized shade you can kind of blend both of this together and this is using uh this layer blending modes if i change it to multiply i get this uh very nice uh colorized hill shade uh which takes the top layer is just a black and white shade it's blending it with the actual colorized uh layer below so this is what i'm going to use as a face map and i'll try to build some analysis on top of this it looks beautiful that looks really cool i like it thanks do you want to switch to the next person's screen so that we always have somebody amy show us what you've got there oh i'm not chancing cue just and streaming at the same time so i'll show you if i do okay let's have a look at vicky's screen maybe vicky you want to show let's look at vicki's screen so i think i'll stop i'll start by just making a symbology for the mountains i want nice um what's always important for the hill shade is to to show the uh resampling uh settings because they uh it can be quite coarse so it's a little trick there especially if you're zoomed into the dm then the bilinear will give better results is there for getting rid of the little squash you start seeing yes and where is it yeah sorry it's on which screen on your screen under resampling zoomed in and then you can change that to a billionaire and you see it so smooth yeah you see it more spectacular if you're zoomed in oh yeah it's very now the thing is that that's just for visual applications a useful one but if you want to do calculations and you are reprojecting dems then you need to stick to nearest neighbor if you want to do calculations because bilinear is averaging values i don't know if the others have opinions or experiences with that but that's what i always advise i'm just trying to figure out how to apply a symbol to a particular um what do you call it levels of symbology yeah oh yeah hmm i think let me move on as i figure something out all righty let's maybe see what charlie's up to in his alien land oh i think he's gone he ran away when you put his name and spotlight no i i he seems to have so let's go on to hunts and see what he's got got up to so far well that looks cool so what's your goal for this well people know me from a hydrological analysis that's exactly what i'm doing and proving how robust these tools are that even if you give some random generated dm that it will work and what i'm using is these new pc raster tools integrated in qgis by the way we are going ahead with having a processing provider plug-in of pc raster ready soon niall dawson is working on it so you'll hear more about that but meanwhile in one of the last uh open day sessions i've presented how to get all these pc raster tools here and what i did was convert the dm to the pc raster format because that is something that's needed it's a gdal format so that's quite easy and fast and then i used ldd create that is here basically that is filling all the sinks in this dm because any dm that you receive in what way it has been acquired doesn't matter but for hydrological purposes you need to get rid of artificial depressions um so that's what i i did here so you need to to put the dm there and then there are many more settings than in other tools that were available so you can control quite a bit how it's filling the dm after that i want to have the river so i calculated this trailer orders in pc raster that is the stream order tool here so it just needs that local drain direction layer which is the flow direction and then it creates the strala orders and then there's an interesting thing that i always like uh to do often get the question how do i get all the sub catchments without having all the coordinates and what you can do here is um you can look at the strala order of the downstream cell there's a tool here it's called downstream and it will get the cell value of the neighboring downstream cell and then there's a rule if the downstream cell is of a different style order it means you are at a junction of rivers you're at the bifurcation that means that that's an outlet of a subcatchment unless you're at the spring or at the outlets itself the main outlet so if you apply that you can get all the outlets and then you can calculate the catchments with the catchment tool here feeding in those outlets and there's a variety of tools for that there's also sub catchment you can imagine that sub catchments are nested so if you are further downstream that it will cover upstream catchments that are part of the bigger catchment that it's part of so with sub catchment you with that tool you will preserve those so it will not cover the previous delineated sub-catchments of course after all this talking you want to see results this is catchments and this is sub catchments and then blended with the uh dm with the hill shade and here are the rivers and later i'm going to show you that you can do this with a model in the model builder connecting all these uh steps but i leave that a bit as a cliffhanger for later and meanwhile going to work on further styling this because that's difficult i saw that tim was working on that mask which is a smart thing to do because my island just goes into the water and those rivers are marine rivers too i knew that but it's just uh conceptually quite difficult a rust there are lots of different steps to to to connect but we still have time maybe i'll do that absolutely anyways very colorful always these catchment maps random colors and here you see the strollers let me switch off and i can style that with palleted unique values select the correct one so here each color represents a strata order of the river of a threshold that i have decided on and you can better use blues here or marco inverted the larger the number the bigger the river so here we see how the river increases to towards the outlet and then if i combine that with the catchments sorry i need a sub catchment one and you can see that each reach has its own sub catchment here that's the whole exercise that i was doing here you need color television for this rayman what are you doing i'm curious are you producing chocolate already of your dm yeah yeah yeah that was that should be my goal yeah no no yeah i could i think make a chocolate for this but um i thought i'd make a sewer system because i learned that earlier today so i thought i have to come up with something new here but um i didn't really manage to do that but i wanted to try the the plugin from brazil we saw earlier today in the session um but i haven't even installed it yet though i'm almost there now and so what you're saying basically raymond is when you discover an uninhabited island the first thing you would do is install the sewer network because there is two million people living on that island are drinking water and yeah all right there are a couple of questions coming in so um leonardo from earlier asks hans the analysis done in pc raster tools don't need a coordinate system to configure in meters to work question mark well it does but this was my advantage here i i saw how ushval solved it by creating an artificial projection pc raster doesn't keep track of the projections it just doesn't do anything with it but of course all these tools also saga and grass they assume that your x and y coordinates are this in the same units as the z so if you calculate a slope the function will calculate the steepest slope in a three by three window but it assumes that the z is in the same unit as x and y so if you use a geographic coordinate system then your x and y will be in degrees and your z in meters probably and then it will calculate the slope in the wrong way but it doesn't tell you it will still calculate and you probably even end up with a beautiful map but it doesn't make any sense my advantage here was pc raster puts all these question marks at in qgis at the crs and which is great i can just continue without bothering about it alrighty and then next um ban kasim is a new member or new to qgis so welcome to the community yay um but he asks are these tools to calculate the catchment in qgis um and can they can you use it to make catchment maps yes you can this is all qgis so but [Music] well maybe a little bit of history there the uh there are grass tools and their saga tools that come with qgis at the moment but this might change in the future and there are already changes happening which break a few of the catchment delineation functions and you need to have the old dependencies or you need to tweak the description files of of saga for example so but it's very likely that these will move out of the the core of the processing toolbox but you can add them later as a processing provider tool and therefore it makes perfectly sense that also other tools are developed like that such as the pc raster tool instead of packaging it with qgis that you can simply install it as a processing provider like you can also do for r and then yeah the sky is the limit it's just this whole lego box of different tools from different providers that you can connect all right great stuff um i'm just checking if there are any more comments hello jonathan from panama um yeah let's continue and maybe check in with uchvil again if you've gotten any further yeah let me just show you what i've got and tim's up next so start planning your great reveal oh wow so yeah i spent a lot of my time doing analysis and one of the longest things that i wanted to do for longest time was to figure out how to do least cost path analysis in qgis and there are tools for cross so you can do this uh there are no native tools yet but i found a plugin that seemed to work quite well so i thought that would be a good way to try this out for today so here what i did was i generated uh random points within the first step and it was i just created a mask which is uh greater than zero elevation uh we don't want to swim while we're doing the this course path analysis so uh i created the mask uh clipped my uh game and then uh again this is uh one of the issues with qgis that's uh that we have uh even when you click there's a precision issue uh with floating point so it doesn't clip exactly at that location so there are still because of the partial pixels uh uh you've still got some negative values and again uh for doing the least cost part uh it's better to have a value between like uh say zero to hundred so i rescaled my raster between one two hundred zero is really bad for these first part because then everything will flow along those cost zero because there's no cost right so i assign uh use the rescale uh tools here so this is quite handy to rescale raster and scale all the raster from like minus uh one minus 17 to 190 to 0 to 100 or 1 200 and once i had that i just generated some random source and destination points within that area and i thought let's say if i want to go from here to all these different places uh how would you go if you were lazy and you didn't want to climb else you want to take the least cross path and this is what the the output that got generated that you know you would if you want to go from here to here you can see most of the past taking the the least cost around just walking around the beach here and then you climbing up in a straight line which is the this caused that for here so this is what i've got so far and i'm going to keep tweaking this and then we'll create visualize this in 3d that's the next step all righty cool so um bg asks they like your interface and how can you change it to gray i'm assuming to change it to dark mode so that you can do in the settings um and then the next comment is that they can't really see um with the contra trust of the dark mode your icons etc that yeah i'm on a mac so this is the qgis mac interface it's not dark mode i think this is the default one so oh okay cool so that's what mac looks like yeah yeah but you can you can switch it to the sort of regular looking one but um i think you're in the night mapping theme um yeah i believe so let me just see which one is i like to use dark mode for like work but for presentation you see sometimes don't see the menus that clearly so all right this is blend upgrade this is the there's one question um for you hans um it's from shabir b um how do or how to how do you overcome stream channel breaks caused by glaciers global warming uh you know that's a very specific question that i've never uh considered but it is it is actually quite quite easy because if you have the the elevation below your glacier then you have your stream system delineated from that base dm so the solution is that you have a different layer for the elevation of the surface of your glaciers and the elevation of the the surface i think that's the only solution and i think there are some uh some products uh from satellite measurements where you can get that information from maybe okay great stuff i think let's um pop over to tim's screen and see what he's been up to there we go um i'm doing uh kind of some some things the same and something's different to everybody else i um i did also make a little 3d scene quickly of my area but what i'm actually doing is um because i want my my island to be like a nice place to loose i'm just designing a ring road around it and then i've made i've made a grid and i'm going to make some like some urban areas with a grid uh road layout which i'm going to use this to just the grid to snap to while i'm designing my road layout and kind of make a little bit of a urban framework that we can take um raymond's sewage system and add to my road network and then we'll have between that and ushval's routing system and um answers river network we'll have the whole the whole deal all in place here so i was about to just uh go and like edit my road layer here and just make a form because i want to um i want to capture the data in a consistent way if i was i had a bit more time i would make something a bit more fancy if i'm gonna just do like a quick and dirty form um using the drag and drop form designer to kind of have some uh uh control the vocabulary of what people type into the form or people being myself at this point um i'm going to try not to talk and type at the same time i'd usually end up in a mess but i'm setting up my road types here so i'm kind of giving them a like a human facing side on the description and the computer a name for the computer to work with on the other side in the comments i think it's litie my my south african eye wants to say it letty um complains that there's no archaeology sad face and ahoy from in slovakia um but you're just gonna have to make the archaeology damn that's the point of freestyling yeah exactly just uh get busy i think we should make this an alien world where there's some alien archaeology that would be cool one tip maybe you can see on the form is i'm just using this now function of qgis so that every every road i add gets a time stamp um and which is a nice way to just make sure that you can keep like a history of when things happen on your map we can i'm planning to use the history later to make some fun visualizations as well i was about to ask if you if you're time stamping them could you later on animate in some way yeah that's what i'm aiming for oh okay okay and i'll just show you another with that form that i just made um i get nice little form here with the date pre-filled in and a list of types of road that i can pick from so next my plan is to start digitizing some city network i'm just trying to decide where the best place to put a city is or another city or town probably the island's not big enough for a city but um i guess uh yeah i probably got to be able maybe over here there's a lovely bay and good for tourism and you can swim out to the to the [Music] uh what do you call this promptless peninsula peninsula thank you so much oh lee t is timber's um screen name hi timmer nice to hear from you you should have been in the room you could have shown us all the archaeology it's not too late you can come and join us yeah absolutely all righty what are you doing there now tim i'm just uh i took the the con i generated contours for the island and then i'm taking the like the first one at about five meters and using that as a as the line for the ring road because if you're an engineer and you're building a road network it's nice to i speak like a like a seasoned engineer which i'm not it's nice to um it's nice to build your road network on a kind of a flat um basis so that you don't have to you know blast away the mountain side as you're trying to tunnel through it or uh what have you so um that's that's the ring road i'm going to set up some cartography rules after i've got a few roads and then i'm going to start my residential network here with a bit of digitizing that sounds awesome i think um perhaps we should pop over to victoria and see what she's up to [Music] you hear me oh yeah i'm making a fantasy map over the dems so i'm just using um the rasta calculator to make masks for specific sections like i've done sort of where the the mount i think the mounting should be so now i want to to put up where i think the level of forests should be using a lot of the histogram to figure out where things are um raymond leonardo says if you need some input on the sewer system he he's here for you he's ready yeah i think i could use that but i i don't think the since there's no map projection uh it's not going to be easy yeah but i'm still trying to install it so um yeah i should actually watch the video uh from earlier this day um alrighty so what is your your plan victoria in terms of your fantasy land um first get the sections that like forest mountain ocean sections together and then now go to the specific sections maybe set up sorry set up uh like a palm tree or something like just on the edge sorry and i'll see where it goes for there from there alrighty that sounds very very cool you showed us how to make little um trees and boxes for our imaginary game world so now this is going to be our imaginary game world all righty let's hop on back to hunts and see how he's gone along with his more hydro themed stuff so here um i've been working on two things putting the other tricks in the model and calculating um yeah the the path from the top of the mountain to to the edge of the dem i still didn't calculate uh a boundary for uh for the ocean but this is the the path if you would follow the the flow direction so from the highest point now how do you find the highest point there are some nice tools here to do that there is a map maximum so use your dm and then it will output at maximum probably have it somewhere here i have probably called this highest point so it's a global gis operation which will fill each pixel with that value of the highest point so if you query that wrong layer here it's this number here 193.7 and what you need to do then with map algebra is to find the pixel which has the highest point so that's this pixel here i will remove the path so that's that's the highest point in pixels sorry i'm a pixel person there's probably some higher point inside or just average elevation of the pixel and then there's the the path tool this one where you put the flow direction map ldd and that uh highest point the highest pixel so not the one that has everything and then it will calculate uh the path that's then that red line here this one and it follows the flow direction so if you need a swim after climbing the the top then uh this is probably your fastest way down if you're if we are still waiting for the others to make roads and other nice stops on the way and visiting archaeological places hi everybody so maybe we can have a look at the model that i was building if you can find it yeah that would be great so here because then you see a bit of that process of what i've shown earlier oh wow so yeah that's a big one yeah i've done similar things before so i adjusted uh on some details yeah i'm assuming you didn't build this in the last um 20 minutes i'd be incredibly impressed if you had no no no i'm cheating a little bit with that but the regulations don't use data from others but they're perks to being hunts for the quest okay okay [Laughter] so uh yeah here's the input digital elevation model the one that the team had generated and then a minimum strata order to determine your what you consider as reverse the digital elevation model is converted from tiff to the pc raster format then this flow direction is calculated and then we can calculate the strala orders and then we need the strala orders uh from a certain threshold so that's that value that you put in here but we can only work with spatial so this function makes it spatial and because it's strala orders it's an ordinal scale so there we get it out of it and then with the if then function we can create a boolean out of that and here we we can check the strala order one pixel downstream and that's how we can find the junctions because it should not be the same it should be different from the one that it was so i used a not equal operator then all those points need a unique id because i want to see different numbers for this for the catchments that we get out of that let me see how to pen that unique id function um produces uh a nominal uh or scalar layer but a scalar which means it's uh it's continuous and it shouldn't be it should be classes so here we convert it to nominal and then i need to add zeros in the map that's what cover does and then [Music] then i finally can calculate catchment and subcatchment and that's then reported so long story but uh this is uh this will be shared i think part of it is already in the resource sharing plugin under if you have added the the repository of pc raster then there is a model section there model collection and there you'll find it if you install the pc raster model collection and these are these three models oh wow okay cool and yeah this this proves it's robust enough to to feed a random dm dip to it and it will produce your rivers like catchphrase well that's really really great to know um timber have you been following along do you have any cooldown to show us uh yes somehow awesome okay so it is as usual about the visualization for archaeology uh you could somehow share the screen uh give me half hour bottom of the screen third from the left the little screen with an arrow in it okay so i got right okay probably you can see my screen yes so i'm usually producing this kind of visualization for the archaeology where you can see the multiple values like the curvature of the digital elevation model the slope the openness to the sky usually i'm trying to divide those two filters to two parts one i called the contrast second is called the curvature but by different way and okay i have the problem with crs and the result is usually a combination of really nice also i believe that open source software it is called raster visualization toolbox it was produced by university in slovenia and they have really nice tools and these tools also work like the plugin for the uh the plugin uh i tested uh i think one week ago only this advantage what i see of the plugin is that it doesn't use a multitude approach and this i don't want to use it then i'm trying to stack those layers with different kind of blend modes you were talking about the multiply many times i'm using the things like uh i don't know [Music] multiply darkness normal and so and so many of those ways how to express the curvature of the dm is symmetrical around zero and unfortunately i'm a little bit stuck in the not in the series but what is on and off so here is the part for the curvature it is based on a simple local relative model but simple local relative model is also known in the for instance in the white box tools like deviation from the main elevation of model then something like local dominance it is really complicated hey how to express the the curvature of the digital elevation model and then for the contrast i'm using the combination of skyview factor uh it is the how you are when you are lying on the ground and you are trying to observe the sky that how much angle you can see and i'm trying to combine combine it with the slope and i'm trying to use the trick that for instance yellow color and green color of slope producing the orange color blue color and red color producing the violet color and somehow when i mix it together the results is like this one and then for this i'm using the map to raster i really like these tools i think it is in the raster tools convert map raster that's the really nice way how you can mix and blend all layer together to one layer and what i see as a big advantages of new formats is that usually by gdel i'm trying to convert it to the cloud of mathgotis because cloud optimization okay the original purpose is to put it on the web and you can download it from the web but cloud optimizative have the nice internal structure of the tiles and overviews so cloud optimizations are really fast on the even on the super slow superview computers so this is the way how i'm producing those things i upload i think to the comment on the github the example of this result and you can play with it and you will see that's so brilliant i love this it's very very interesting i like to see the archaeology application i think we're going to hop over to urjuval and we'll come back to you at the end and see what you've been coming up with this is brilliant okay but i i have to say to goodbye to everybody because tomorrow i'm moving to the excavation in egypt so i have to prepare myself but when i saw so nice topic so it was really nice to meet you oh it's good thanks to bruh and enjoy the excavation thank you yeah i love how the blend modes and combining different outputs into a single image can actually bring out so much detail so that's awesome yeah it's a fantastic all right uh so i have i remember my 2d output that i had generated in qgis we had a dim and some viscose part and i used the excellent huges to 3gs plugin to export that map to a web interactive webmaster and here's we have the map the same map that was in 2d now it's in a browser running in 3d we have the source point in this nice green cone and the destination points here and you can now visualize uh this data on how the least cost path flows and this is also a really nice way to validate today i always like to validate my analysis and say that this survivor did the right thing and you can kind of see that yeah if you want to go from this point to here it's best to just climb down here and walk along the beach uh or uh you know so on so i think this is a great way to visualize and also see the the really nice uh 3d den in action and just thank you yeah thank you one of the things that i kind of took a while to figure out is like i saw this really nice cortical markers and uh i was just about to ask about those how did you get those yeah so let me just uh pop back to qgis and uh essentially once you have a map that you like you can just go to install qgis to 3gs and open it up this is what it looks like you need to set a base elevation so this is the elevation that the 10 bit we had and then you can add on point layers so here we have source and destination layer but this would just get rendered as you know points so you can right click on this and go to properties and there you have an object of how do you want to place a marker and there's a cone marker the default one is a cone that is upside down like a regular code so to turn it upside down i uh just tried it negative 30 in that work i think that works much better as a marker so yeah i said the z coordinates are 30 and then height is minus 30 and that's how you get this conical uh and one other thing that you need to remember for the skew just to see this plugin is that it assumes your horizontal and vertical units are the same uh units uh so in this case it's fine it just uh takes it up but if you have a regular dam where it's you know it's in geographic crs and your elevation is a meter uh make sure you reproject it to a linear projected crs before using that and then you can set some scene settings there are some settings here if you want to use some vertical exaggerations and stuff like that and once it's done file export to web and you get a folder full of javascript json files and html and just opens up one other thing if you want to just visualize it on your computer make sure you check this enable the viewer to run locally it will disable some of the security uh settings so you can view that locally and otherwise if you're sticking the server disable that put those files on a static server and you have a 3d map so that's it i'm done and i can now enjoy other presentations oh that is awesome i love those little conical markers i think they're the coolest thing ever alrighty um raymond have you come right do you have any cool um networks to show us no i don't i'm actually still trying to to to make the plugin run that's all right we will then come back to have any uh sewer system for these uh poor people now i enjoyed watching uh what you were doing and uh i think the way that i am in the doing this kind of roster analysis i think so uh thanks as long as they're not using the river systems that hans is creating we do need sewer systems on this island um but let's hop over to um vicky and see how she's doing making a forest for our lovely imaginary people let me just try and get on um just while victoria's sharing um ban kasim who is new um just wanted to ask obviously you guys are all cuges gurus but as a beginner how should he start with cue just sort of what is the best website so i know you guys sort of know the best places to go i have a couple of ideas that i will put into the comments but you know as an absolute new user where should he go and what should he do well the documentation of users on the website well tim yeah yeah if if you can afford to there's some very good books um that i would recommend just getting a paper book that you can put next to you on the desktop um on your on your on your desk while you're working with qgis because it's maybe it depends on your personality but i think it's the easiest way to get going and you also can support a lot of the authors from the qgis community which is also nice so locate press if you can drum up the link and put it in the chat there i mean they've got a bunch of nice books um at different levels on qgis so that i really recommend any of the books that they produce are great and then on the website qgis we've got a training manual and we've also got the documentation the training manual has got like step-by-step guides for doing things you can do all self-paced and that's where i started and they're awesome and the user manual is more for like if you want to find out like oh how does this particular feature work um it's good for going and figuring out those things um and then looking at blogs like ujvol who's here in the courthouse got a brilliant blog and um uh i think most of us in the room europe got some kind of like presence online where we we publish what we're working on and um just reading what people do and getting tips and also the we've got the the telegram channel which again amy can put the link online for you that's a really great place we don't mind any there's no question to done as long as it's sort of on topic and polite we really like helping people there and you should sort of embrace the fact that we're a community of users and we're all out to help each other so nobody's there's no big egos you can just ask any question you like somebody will be there too to help you if they can and if you do ask a question they just be patient you know somebody maybe people are busy but you know just ask again nicely if nobody heard your question sooner or later somebody will try to help you and also another good thing to mention is if you are asking for help just try to put your question clearly and so that we could got enough information to understand what it is you're trying to do share the sample data if you have it or um you know just make give us enough information to help you and then the best thing to do is just do what you're doing now in this session just get keys open and start to play and see if you can make it do things and it's nice to learn software out of the pressure of a client wanting something or your boss wanting something i think every qgis user who's gotten addicted has a highly over-engineered map i know tim has one not of his farm that is amazing i have one of birds and bird sightings and on my phone and on qgis that i'm building so i think every qgis user who started starts from a really small map that they just then engineer with every new tool that they learn so that's a really really great thing to do for yourself and then upside at the end of the day you'll have something in your portfolio that you can show as hey these are the cool tools i can use um in cuges etc so i see victoria you're up to something what are you doing um i'm trying to build the forest but i can't get this is something i'm not able to get right on the i think on my raster calculator is what i'm trying to mess around with just to see what happens hmm what i'm trying to do is get the values in the middle of the range that i picked but that doesn't seem to be working all right well you figured that one out i think let's pop over to tim and see what he's up to if he's got his town ready it's on the side of a mountain i'm all over the map as they say i've just been digitizing i'm using some of the nice digitizing tools to kind of trace along you can see it sort of oopsie that one didn't it rates along the um coastline and i'm just demarcating different land use areas here so let me just quickly finish that one there uh so i've made another little form and i'm busy digitizing different land cover classes my town i've got it's astana level here i only digitized six roads so if i was i um tend to have a short attention span so if digitising roads gets just too boring then i jump to the next thing and um but what i did what that's interesting in the roads maybe for those who are interested in the sort of cartography techniques in qgis is that i use some capping styles you can see my roads i've got round endings and i used this more advanced thing called symbol levels in qgis you can find it if you um in the styling panel in this option here symbol levels and what they do is basically prevent different parts of the symbology over laying on top of each other so i can show you a simple example if i change that from two to fifty or something like that you can see that road turned black but basically the stripe in the middle of the road um is drawn underneath the outer cap the outer lines of it so like i went and just constructed things so that you can see how the roads they join in to each other smoothly and they don't like you don't have things laying on top of each other and also made some rule-based symbology so that when you zoom in and out and the symbology changes to a more simple version of the road so it's not too visually cluttered and for the coast in a real life world that would kind of be your main road and then all the secondary roads would disappear at different scales yeah or maybe change from a thin line to a thick line as i've done here and then also for the coastline i just used this shape burst full which is a nice i use the inverted polygon so i copied the same technique that hunts and um i think gujarat also did a mask and there's a copying going on here and or i should say use the same technique yes and um so that i created like this little fuzzy coastline effect that's really cool i was playing also with the with the dem i actually used the trick to which i think victoria and i or you you and me and victoria i don't know we recorded a separate video about it about making um like pre-rendering the hill shade to make it really performant so yes i remember yeah instead of doing the hill shade rendering on the fly i actually um i created the shade and i basically just used the export save as properties but instead this is the default to export the raw data but i exported the rendered image so that i've actually got a layer like um which i can probably show you here which is the tiff which is already rendered as as the dem uh sorry as the hill shade and that way and i use the cubic convolution resampling of the the bicubic what's called resampling as well so that it's it's all smooth and everything but it's just rendered as a picture rather than trying to complete that on the fly um normally i change it to a bite which is what what these funny bright things are yeah but i don't know something went wrong i actually did a command line here to convert it to a byte but i think i still missed something i probably need to add some extra compression options because normally if you do this you can make it a really small file and i think i left out the compression options so it's not quite as small and now i'm busy making land use types which i'll show you in the next chicken if we have time for another chicken yeah absolutely alrighty well um speaking of next chickens i think we can hop over to hunts and see how his um hydro stuff is coming along um if his rivers are ready for us to slide down well since raymond wasn't yet yet ready with the sewage system i have added a pollution layer it's just some random pollution just thinking because the houses are also not ready i've seen so people are just uh nobodic living on that volcano here i assume it's a volcano but of course we need to do some field work with the input app or q field let me see the pollution layer what i did i created a normal distribution you can do that with the normal function but it needs an input boolean layer so that means a layer which has only zeros and ones so i filled the whole dem with once and that's what you can do with the spatial function here i give here value one i say it's boolean so these are the data types that pc raster is quite strict on and then a mask i choose the dm and then it will generate just a raster of the same dimensions with the value that i chose here in that data type and then i use that normal function but the normal distribution is uh with zero uh as an average so i added uh 10 to it now here i had to cheat a bit and and not cheat you can do it with these tools but that's for me it's faster to do that in python let's say hack a bit yeah so what this uh this does here um wait yeah it starts here pollution is read that normal map from disk and add value 10 and then write it back to disk that was just my two lines here to to get that pollution layer here so then it's not between minus one and one with zero as average but some pollution nutrients human excrements between five and fourteen units and then we can route those units over the landscape using the aquaflux tool here which accumulates material flowing into a downstream cell without removal there are here all kinds of other tools when the sewage system is finished that we could use or when we have all kinds of measures in place that remove pollution but since we don't have that we end up with this i need to switch off the pollution layer so in the background you see our hill shade and then here in it's always very difficult to color that but because the ranges are very large it's exponential so the trick there is that you uh use cumulative count so you can see the the higher numbers better represented than the lower less and then choose a ramp that where red is bad a lot of pollution so the red lines here is where uh all the mass goes if we don't have a sewage system i think we better get um raymond and leonardo on to the sewage system or else we're going to have a lot of pollution problems oh yeah and i fixed the fix the island in the meantime today um the above water and then yeah this shoe does already look nice also tweak the styling a little bit yeah so everything below the sea level is is value zero and then of course the hill shade is still visible below that so the blue part is below zero but the batimetry is visible that's the idea okay cool so we're seeing a bit of ocean floor there yeah exactly all right brilliant stuff all right so we're running a little bit over time so i think i'll do a last sort of check-in with everyone and see where everyone is at and then we'll finish up so i know uchvel you did say that you finished last time so i don't know if you wanted to add anything or just a comment yeah i'm done i've been enjoying the other learning some tricks from other folks and i'm just creating an animated gif out of the the final thing uh qgis to 3ds doesn't have a built-in animation but they have a mode where you can rotate uh the model so the webview just rotates and just call a screen recorder capture that converting to a gif and just gonna upload that as my result oh that would be awesome absolutely cool i can't wait to see that alrighty so next on our list is tim let's see where you're at uh not too much further i was just busy making a label so maybe i'll quickly show you a labels layer to put some um kind of nice labels in the in the c here so i was about to just do something like this with the um let's see just digitize the curve here uh like this and then we're gonna call this um just ocean i don't know not very original but anyway that's and then i was just going to set up my label properties i'm going to basically label this with a nice label running along there i might have to just use the switch reverse line direction tool here quickly to just [Music] select it this is just a little trick if you if you type in this corner here you get like a quick search for all sorts of functions and data in qgis and some of them will operate on selected features so i'm just going to reverse the line direction of this line and then uh okay it's done but you can't really see a difference yet and then i was just going to make my label curve nicely along that line by telling it to go here curved and maybe gonna just pump up that size a bit like oh tim we lost you well at least we lost your screen uh my screen is okay i'll just stop it and if you can see it now and um here we go that's where i met that's brilliant i love the curved label you know i was i was messing around with that last month for um the waterberg area so i like making that sort of thing and just making everything a little bit unique um so this is looking really really cool um you've got your land uses are there any specific clan juices is there like a well that's the beach zone settlement areas and some forestry and some rocky outcrops which yeah maybe a bit bigger compared to the rest i should have dug a volcano in the middle like hunts that i feel my geology is not as exciting as this anymore all right great thanks so much tim i think we're going to hop over quickly to vicky and see where she's at oh this is looking cool i'm vicky you're on mute so i finally got the forest working now i just got um this you can see on the side a paper sort of paper texture that i i got it from us one of this hugest templates i can't really find it in all my tabs right now but i want to just sort of through it over to give it a an old old map sort of feel i'm just test that out for a second so this is what i the paper texture sort of looks like now i just want to lay softly over the over my features hopefully that works in a few minutes all right brilliant uh hello edston from tanzania who's commenting in the comments no this is looking absolutely fantastic i like the idea of making look at sort of old-worldy i think it's really cool to have your own sort of unique mark on a map um and using an already made um huge style especially using the qgis styles repository um if you are a new user um ban kasim do definitely have a look at that um it's on the qgis website i did share a link at some point um so do you have a look at that because that's got a really a lot of really cool sort of pre-made um styling that you can use in your own projects um and then i think that's everyone unless raymond has some comment for her for us yes there's a little progress so i'll share my brilliant show us we may no longer need the pollution map i hope so here's the little thing is that i um i managed to get the plugin up and running oh brilliant there but whatever button i press uh is not really uh doing a lot i tried a few things and here's a a three one thing now suddenly and i don't know why i really cannot reproduce what i saw earlier today but um at least there are some something to to show i'm sorry it's just that it's a start no that's great it's very very cool and thanks to i'm leonardo for helping along and being support for our sewage system for our little alien world um and yeah i think we're about 15 minutes over so unless there are any other comments from our amazing team um uh just maybe from me to say that if you all those that participated both here in the jitsi room also uh following along online if you attach them to that link which uh amy is hopefully put in the description of the of the stream um maybe we'll wait till tomorrow and then we'll see what what's coming by tomorrow and then we'll have some highly democratic process to elect the winner not [Laughter] well sure vote on them somehow and uh send you a nice coffee mug are those just github links tim uh the one to the github issue one yeah that's yeah yeah that's at the top of the chat so just if you are submitting scroll up also please put your working pictures or um i know is going to have a really cool moving 3d video for us um please do put it on the telegram channel so that we can all comment and have a look at those and thanks from me for everybody who joined i hope you all had fun i had a good time it was great fun and learned a lot thanks for the idea thanks for hosting me i think it was a lot of fun hopefully we'll have another one of these soon um and thanks everyone for joining us um the next q just open day will be next month i'll probably start planning in the next couple of weeks so if you are interested in doing a session or getting involved please just um send me a message on telegram or even twitter whichever social media suits you um you'll find me there i'm usually aimed at some point so please do check us out all my info or contact information is on the wiki pages so i just want to say thank you to our amazing team of qgis wizards we always learn something new from each other and from you so thank you so much for taking part in our little freestyle session and that is the end of this month's qgis open day thank you all for joining rock on thank you everyone

Channel: QGIS

Views: 1,557

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Id: ZLmdft26seE

Length: 77min 30sec (4650 seconds)

Published: Fri Aug 27 2021