Blender Landscapes Tutorial 1

hi everyone I've been meaning to do one of these tutorials for a number of years and I have repeatedly failed to do that but here we go this is the first time that I've done one of these so what I'm going to talk you through is the process involved for creating maps and landscapes from GIS data mainly digital terrain models and lidar data so the first thing that you will need is some lidar data or some elevation data and you can get that from a number of sources but there's some really good open data available from local governments such as this portal here from the Scottish Government and what you'll get when you download that data is tiles of DTM or DSM data so when you import that data into GIS the software interprets the elevation as an image a grayscale image where black at the lowest parts and white at the highest and then a sort of stretched gradient in between but the issue is with blender is that when you import that data it doesn't necessarily deal with no data values very well so there are quite often a number of steps involved in GIS in terms of processing that data which I'm going to take you through so you might want to stitch various tiles and mosaic them together all you might want to resample that data if you have very large data set to make it smaller or even reproject it so if we switch over to blender the first thing you need to do is if you press a to select all the objects and delete and then we get rid of those default objects and then we need to enable an add-on so in edit preferences if you search for image we want the import images as planes option and what that allows us to do is go to file import images as planes and then if we choose one of those lidar tiles and import it what it does is it Maps that image onto a plane and we can see that by switching render engine two cycles and then the viewport shading in the top right corner to rendered and what you might notice is this is the same data we were looking at previously is that blender doesn't properly interpret that no data value so that the lowest part is very low in terms of values and the highest part is white and this part of the any sort of gradient of gray in between and if we inspect that data in there for me you can actually see clicking on the values that the no data value is a minus 9999 so when that image is stretched across that the whole data range blender doesn't properly interpret those values so not to fear we can do something about that and there are a number of ways of stretching those values across the entire image so even this one here that looks to the image looks to completely fill the valleys there is some very small holes which are filled with no data so in in ArcGIS you can export a different version so different raster format so typically what you might want to do is use say a 16-bit TIFF or PNG and if you choose this option here a scale pixel value what that would do is properly scale all of those real elevation values across the entire range of the image however if you're lucky enough to have there for me there's also a tall transformer called the raster interpretation coercer which would do that job for you so here we're reading in g8 if DTM and the rest are interpretation cover so is set to a 16-bit grayscale image which will still provide you with a very detailed high-resolution image but it will drop the bit depth down to 16 bits rather than 32 bits and it will do that job of scaling those data values across the entire image okay so now what we can do in blender is delete that one there and then import our properly scaled DTM grayscale image so I have made one here called Aran DTM so this is on the Isle of Arran in in Scotland and it's some really nice 1 meter resolution dataset so now if I import that image we should be able to see the difference that that scaling is made so it's a little bit gloomy so we will add a sunlamp and if you go into the light bulb here click use nodes you can increase the strength of that Sun lamp so this is that same DTM tile that we are looking at here but those values have been nicely stretched across the entire image so in terms of making landscapes and terrain models in blender there are a few different approaches this one to do with making a mesh or a surface there is one to do with displacement and there is one to do with micro displacement or adaptive subdivision I'm going to show you a few of those displacement options then maybe another time I took show you the sort of surface or mesh based approach so the first method I'm going to show you is called the adaptive subdivision method also known as micro displacement and this is quite a clever function of blender in as much as that it will displace your geometry and give you as many faces in that mesh as you have pixels in your texture so it's capable of producing very detailed and high resolution meshes in this case terrain models but it does have some limitations in as much as the it's firmly found within the experimental feature set within blender so it's not fully supported and integrated into all of blenders functions but I'll show you - both approaches so if you change that feature set to experimental in the scene settings and then the next thing to do select your playing and add in the modifiers a subdivision surface modifier choosing the adaptive function and where it means it's adaptive is that it will dynamically produce a displacement but it also does some clever things like the portions of the mesh that are closest to the camera will get subdivided more so give you more detailed and those further away will give you less the next thing to do is open up the shader editor and you need to add in a diffuse shader connecting up the color output from your DTM into the color input of the shader and then we need under vector group a displacement node again take your DTM but this time connect it up to the height input of your displacement now you can see that it starts to give you a bit of a hill shade view but no actual displacement so it's still very flat to make this work go into the materials settings and change the displacement type from bump to displacement and so you can see it's completely changed the geometry based upon the DTM now this is obviously massively exaggerated so if you go into the displacement mode settings and change the scale to something a lot less like not point zero five and this will give us a bit more of a realistic terrain a couple of other things to change in the subdivision settings change the preview rate from eight to one that will give us a preview of that render at a much more detail level so starting to look a bit more interesting but you can see this is still really quite flat and that's because of the Sun it's pointing straight down so not really casting any shadows to change that go into the transform properties of the Sun and give the y-axis on the Sun some rotation you can see as we start to do that it starts to cast a lot more interesting shadows next in the let's on lamp settings you can play with the angle setting so if it's zero you get some very hard crisp shadows and if you increase that you start to get some slightly softer and nicer looking shadows next select your plane and in the shader editor add in under the convert as a color ramp and here we can change the color of our DTM from grayscale to something a bit more interesting you change the interpolation to B spline this will give you a much smoother gradient as well now I find it works best if you use some fairly subtle pastel e-type colors and you can go you can go mad with this and choose any particular gradient that you want generally the subtler the gradient the colors and the better it works so this is OK and it works well but it does have some limitations so I'm going to show you a different approach this next method is just using the regular displacement functions in blender so go ahead and change the feature set back to supported and we can then delete our displacement node so this method requires a manual subdivision of our object so to switch to edit mode and then in the edge menu to subdivide and if you do shift R that will repeat the last function in blender so keep subdividing that mesh until we get a very regular grid of faces as detailed as you like it was as detailed as your piece can handle so now come out of edit mode and we want to add a displace modifier and we can get rid of the subdivision modifier for now next you want to choose a new texture to use then in the textures tab down the bottom it shows you this is the displacement texture you want to choose your DTM to use as the basis of that texture now again this is producing a very exaggerated terrain and it's also got the wrong mapping of that texture so in the modifier settings change the texture coordinates to UV so these UV coordinates were created when the import with planes tall added that plane to your texture and we can change the strength again back down to something a bit more reasonable so now we have some less detailed geometry but much lighter and easier to work with one of the drawbacks of the adaptive subdivision is that it's a very heavy process in terms of your CPU and I find that you can achieve the same overall result and have a much lighter model by using this regular displacement method so now if you're happy with the levels of subdivision which looks fine to me we can apply it and now if you go into edit mode you can see the actual geometry has been changed so it's no longer a flat plane but it's a bit bumpy so we can go and change the object settings to shade smooth and to smooth it out further we can add another subdivision surface modifier but you might be thinking ah this doesn't look quite as good as it did before it still has the same geometry but to add the detail we can cheat and if you choose in the vector group a bump map we can artificially add the detail back in using the normal mapping function so not connecting up the displacement but choosing to use a artificial bump so a texture to give a an appearance of detail if you dial down the strength you can get something that looks just as good in my opinion one of the things I've been asked quite a lot is how to get different layers of GIS data into your scene so that they are mapped and positioned correctly there's a couple of ways of doing this you can import things like FBX or obj files with 3d features in them or you could import 2d features and drape them onto the surface but the positioning of those is quite a tricky thing unless you've compiled them separately and in another program one of the methods that I like to use which I'm going to show you now is to use textures to layer up different masks made from very simple maps created in GIS so for example in GIS here I have some features from OS opendata from I assume stack of the water so the surface water lakes and rivers so you could create a very simple map just with a black outline and a white background in GIS and export that to an image or as part of my same FME workspace I'm going and taking my raster data swapping its geometry with a bounding box and then using that to go and fetch those OS features using a feature reader now the secrets are making that the positioning of the textures work is to clip your images so your layers of of maps to the exact same proportions and size as your source DTM and here in FME I'm just simply doing that with a clipper and what you end up with is a very simple texture which is essentially a mask for the water and so you can produce various different ones for different layers so this is woodland for example so back in blender you can apply those by adding those textures into your shader so choose image texture and then open water and then using a shader called a mix shader' you can use the water mask as the factor to mix different shaders together so now if I add in a glossy shader to give the appearance of reflection on water you can see as I rotate the model it now has that texture mapped onto it which is controlling how those different materials are mixed together so you can go ahead and add as many different textures and mix as many different shaders together as you like so it's also possible to mix textures and colors of textures as well as mixing shaders so if I add in another texture now and one for the woodland mask that I'd made you can take the DTM gradient and in the color group add a mix RGB node again using the woodland as the factor to mix those two things together I now have muddled woodland features mapped and what's quite nice is that you can mix these in many different ways using the blending modes so similar to things you'd find in Photoshop where you could say darken or multiply or add colors rather than just mix them together it's also possible to mix the colors that effect the bump map so to mix in different shades of grey into your DTM so I'll show you what that looks like now so again add a color mix RGB node and here if we add in the woodland into the factor again you can see that that's giving it a space sort of subtle and drop shadow to that woodland feature now obviously that looks a bit strange but if you were to go and play around with this mix node and actually mix those colors together you can adjust the factor to get a very hard edge or very very subtle feature on that woodland so we're starting to build up some layers in this and it's looking nice so that's about the end of this tutorial I hope you've enjoyed it hopefully I will follow up with some more on rendering and adding different layers such as particle systems and trees and that sort of thing thanks very much

Channel: Owen Powell

Views: 5,912

Rating: 4.978261 out of 5

Keywords: Blender, 3d, GIS, landscapes, map, DTM, lidar

Id: oeVUWTSkAlk

Length: 20min 51sec (1251 seconds)

Published: Fri Apr 24 2020