Blender GIS: working with custom raster and vector data

in this video you're going to continue learning blender gis however this time we're going to work with custom data so you will learn how to import a custom digital elevation model that has a higher detail and resolution than the model that you worked with in the previous video you will learn how to add levels of subdivision to increase the detail on these digital elevation models and after that we're gonna look into how to import and visualize vector data so basically shape files that use in gis environments so i'm going to show you how to add those and change the symbology by using blender objects so let's get started so start with a fresh blender file and ensure that you have the gis add-on enabled start with deleting the default cube and go to gis and we will start with importing a georeferenced raster or our dam in fact so hit geo reference raster and navigate to the folder with the data that's provided for this course then select this one however the coordinate system that is used by these maps is not in either of these two actually it's by the ed50 utm zone 33n so universal transfers merchant or coordinated system uh and you have to add this to your geo reference drop down menu so how to do this add the plus and then search search utm33n hit enter and then you have a list and then you can select it from this list then save the add-on to add-on preferences to ensure that is in this list okay now we can work in this coordinate system what else do we have to set so in order to make sure that the dam the ditch elevation model is turned into a three-dimensional mesh we will have to select this option them as a displacement texture and what this means i'm going to explain to you in a bit so otherwise keep the settings as they are as you can see the resolution or the detail of this model is not too great however the actual resolution of the digital elevation model is way higher than is now visualized so to increase this detail to the original detail of the actual digital elevation model we have to go to the modifier properties and here you can see what the import of the uh with the blender gis add-on actually did it added a surface a very simple surface just four points a plane with four points so two things were added to this simple square one of these is the so-called displacement texture and to explain better how this works we're gonna turn to qgis in order to see what a digital elevation model actually is and you may know already that digital elevation models are in fact raster images in which the cells or individual pixels of this of the images have a value and that is not a color value but it's an elevation value so in this case when it's visualized for in on a scale from white to black white represents very high values while black represents low values and blender can read these values using a displacement texture a displacement modifier i should say say so the displacement modifier takes in this texture the the digital elevation model and then this places the geometry um in relation to what it sees on the image so basically when it has a pixel value of 20 meters over here it pushes the mesh up 20 meters and when it has a pixel value of 200 meters over here on top of the hill it will push it to that level however it does need a certain amount of geometry in order to do that currently i will change the visualization mode a little bit currently this is the level of geometry it's quite coarse as you can see so there is not enough geometry to get to this high level of detail that is actually possible with the with the digital elevation model that we have so what we have to do is to add another subdivision surface because this is called a subdivision surface and i will show you what this does i add another subdivision surface and actually i should move it up to the stack and then turn it to simple and as you can see i will turn on optimal display here as well you don't have to turn on off optimal display and as you can see the addition of this subdivision surface increased the level of detail of the mesh so we can increase the levels of subdivision even more by changing this property one three four five so each step you see uh the the you see that the detail increases significantly so now we turn back to this visualization mode and i will show you the difference between what it previously was and what it is after a couple of more subdivisions so is it possible to have a image projected on this digital elevation model again like we've we had seen the previous video well yes of course it is so you can project any custom image that has the same geo reference information as this adovation model so go to gis and then import georeference raster and then we select google maps export and then you have to select here this on the right side base map on mesh and then you have to select the mesh on which onto which this image is projected so with this set hit import georester and as you can see it projected very nicely on the digital elevation model and you can also see that the image from google maps was actually smaller than the area that the digital elevation model covered you can see if you change the visualization the shading mode you can see what's actually happening however for the moment being we're not going to work with a image projected on the elevation model so to remove it we're going we're going to material properties and then we hit this x takes a while if your computer becomes very slow right now you'd better turn down the number of subdivisions in order to speed up the working so back to the material tab we make a new material and it's automatically applied to the entire surface we take change to make it a little bit darker so we can see it better and you can change the specularity and the roughness also a little bit but actually it makes it less well visible so we turn it down and oh it's becoming all very icy let's turn down the iciness a little bit something like that but rather than working with a projected image on this elevation model we're gonna use the terrain analysis functionality in blender gis and this time we're gonna work with this slope material because this landscape is actually quite interesting in its slope differences so with a very large lowland plain steep hills and then again a flat mountain surface so you can change the color ramp a little bit if you want i will change this to a type of green that i can see better as a colorblind person all right something like this is fine i want one more level subdivision to increase the detail yes that's more like it next we're gonna import vector data in fact this is a shape file that comes from gis and represents a distribution map of archaeological sites in this area so to import those go to gis and then import shapefile look for where you stored the data and then choose nova territory sites import shape and then you have to wait for this to show up and then it's important to assign a elevation source so it can take the elevation of course from this digital elevation model but it will take a very long time to compute because the elevation model is so detailed better still is if you have added already elevation data to your shape file so in this case there is a field in this shape file that is called height and this will make it possible to plot all the sides on their right elevation so we don't want extrusion but we do want to have separate objects and i will show you why because we for the symbology that we're going to apply later we need to know what type of site gets what type of symbology so i want to separate the objects and have them their name according to their site type and in this case site type is basically stored in settlement so in the settlement fields okay we're ready import okay so this basically creates a lot of points single points and it's created on the right side in the outliner a separate uh collection called norbert territory sites that's very convenient and here you can see in the names of different types of sites so you have sites or settlements that are a very high density or large settlement and there's a type that's called hilltop sentiments a medium-sized settlement sites that are identified as no settlements sites that are identified as single objects fines and sites that are identified very high village urban center and two road stations so how to give these different site types different kind of symbols in blender that we can visualize on top of this landscape well to do that we first have to draw our symbology so you make a new connection you call this symbology and we for the moment go into i hit 1 to go into site view and i position the 3d cursor with shift and right mouse button here above the landscape i hit shift a and i create a cube the cube will be the first symbol takes one it's now very small it's just two meters in size so we'd make it something like well so we take 40 meters we can all adjust the size uh later so we have a cube now and if you want you can adjust it a little bit to your liking and we can add a color a new color to this symbols and we make it blue turn down specularity roughness a little bit and we call this type one type one so the object is called type one and the material is also called type one and now we have to make sure that this object replaces all the sides that are from a certain type so we go to the archaeological sites and then we take all the sites that are for instance very high we select them and after that you select them by hitting the first one here and then shift selectors and shift this one last and then to copy this information basically into these objects you do the following you hit ctrl l and it gives you the links menu and then we make links with the object data and what that basically does it copies the object data from the object you selected last to other objects that you have selected and as you can see now all these objects all the points which i type very high are now replaced by this cube and the nice thing about having this symbology over here that you can just go into edit mode and still adjust it all and everything gets updated at the same time because they are basically linked copies so we can do this for other sites as well i let you do this yourself because it gets a bit repetitive if i do it i will give you an example of what i did in a different file i created five different objects and in my symbology type one two five and i associated them with five different site types actually i combined some side types because i was too lazy to create another object you can do the same you can create three and group some site types together under one symbol or you can create a whole range of objects and just be creative you can create any type of object that you like in blender of course so when you're finished creating your symbology and assigning them to different site types you can hide it in the viewport because we don't need it for the time being so the basis for our visualization is set now we can move on to the next subject the lighting and the rendering of the scene this will be the subject of the next video so thank you for paying attention and see you in the next video

Channel: 4D Research Lab

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Id: t9CH-cg8scc

Length: 19min 24sec (1164 seconds)

Published: Fri Oct 23 2020