{"id":2086,"date":"2018-05-16T12:09:01","date_gmt":"2018-05-16T00:09:01","guid":{"rendered":"http:\/\/blogs.lincoln.ac.nz\/gis\/?p=2086"},"modified":"2018-05-16T12:09:01","modified_gmt":"2018-05-16T00:09:01","slug":"an-arcscene-tutorial","status":"publish","type":"post","link":"https:\/\/blogs.lincoln.ac.nz\/gis\/an-arcscene-tutorial\/","title":{"rendered":"An ArcGlobe Tutorial"},"content":{"rendered":"

In this post we look at how to use ArcGlobe for 3D visualisations of large areas.<\/em><\/p>\n

One benefit of using GIS is the creation of 3D visualisations using geographic data.\u00a0 Often we can use ArcScene to do this, but it doesn’t take long to butt up against its limitations (speed, quality of display, fiddle-iness…), so in this post I’ll advocate for the use of ArcGlobe as one alternative (ArcGIS Pro<\/a> is another good alternative but on a bit steeper of a learning curve – you’ll need crampons, ropes and safety gear.<\/em>)\u00a0 ArcGlobe has the same look and feel as Map and Scene but has some extra added benefits of display and flexibility.\u00a0 When opened, you’ll see something not unlike Google Earth:<\/p>\n

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A few things to highlight here before we go on.\u00a0 The Table of Contents has three sets of layers turned on by default: Floating, Draped and Elevation layers.\u00a0 Elevation layers give shape to the virtual globe – there are two elevation models built in, one at a 30 m resolution and the other at 90 up to 1 km, depending on what part of the world you’re looking at.\u00a0 Note that you can add your own elevation layers if you’ve got a higher resolution DEM.\u00a0 Draped layers are like a bedsheet thrown over a piece of furniture – they take on the shape of the underlying elevation surface.\u00a0 By default, an Imagery layer is loaded as a disappointingly out of date satellite image.\u00a0 Floating layers are layers on the globe but not attached to the surface (in the help files<\/a> they give examples of airplanes and clouds…).<\/p>\n

Many of the tools should look familiar though some are new: \"\"<\/a>\u00a0 These are the navigation control buttons.\u00a0 The 3D navigate tool at the left is used to move your viewpoint around.\u00a0 With this tool active, you can left-click-hold and move the globe around.\u00a0 To zoom in, right-click-hold and drag the mouse down (towards you) – opposite to zoom out.\u00a0 Or you can use the mouse wheel to move in and out. Hold both buttons down and drag to pan the view<\/p>\n

There are two navigation modes: global and surface.\u00a0 At first the global mode is set and you can pan around much like you would in ArcMap with a view looking straight down at the ground.\u00a0 In surface mode you can tilt the view and get oblique views.\u00a0 Toggle between the modes with the mode button: \"\"<\/a>.\u00a0 In global mode I might navigate here:<\/p>\n

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Switching to surface mode, holding down the left mouse button and zooming\/panning, I might end up with something like this:<\/p>\n

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Now I’ve got an oblique view with a bit of perspective, so very Google Earth like.\u00a0 Holding down the left mouse button lets you change the angles.<\/p>\n

But wait, the fun’s just getting started.\u00a0 We can add any spatial data layers we like and drape them over the elevation surface.<\/p>\n

The Add Data button gets us access to our layers.\u00a0 I’ll add the Landcover Database layer (a vector layer) for Canterbury as an example – it lives at J:\\Data\\Landcover_database_4\\lris-lcdb-v40-land-cover-database-version-40-SHP\\CanterburyLCDB4.shp.\u00a0 I get this screen first:<\/p>\n

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This allows me to set the scale at which this layer is visible.\u00a0 I tend to leave it at “Show layer at all distances” but this windows allows you to set minimum and maximum scales at which to display layers.\u00a0 Click Next:<\/p>\n

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We can use this to set features to real-world size if we want.\u00a0 I generally accept this and click Finish.\u00a0 The layer is added to the map but for some strange reason is usually place under<\/em> the Imagery layer and is therefor not visible – dragging it above that layer, symbolising by landcover category and adding some transparency gives us:<\/p>\n

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(To be fair, I’ve thrown a lot of data at Globe this took a wee while to render.)\u00a0 Once on the map it was pretty easy to navigate around.\u00a0 So that’s how it works for vector data – raster data are a bit different.\u00a0 I’ll turn the LCDB layer off and add a raster layer of a viewshed originating at the Lyttelto Timebal<\/a>l.\u00a0 The first window I get when adding the data is this one:<\/p>\n

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Earlier I mentioned that you can add your own elevation layers.\u00a0 Globe recongises this as a raster layer and anticipates that I might be adding my own DEM.\u00a0 Here’s where I can make the choice.\u00a0 In this case, I just want to drape the raster over the elevation surface to I stick with using this as an image source.\u00a0 Again, it inserts it under my Imagery layer (argh)<\/em> so next I drag it on top, play around with the symbology (set the non-visible cells to No Color, reset the visible cell colour, add a bit of transparency and reset the view):<\/p>\n

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This is a nice way to demonstrate how viewsheds are driven by topography.\u00a0 Once it’s rendered, it easy to rotate the view and move around – try that in ArcScene.\u00a0 You’ll only get frustrated.\u00a0 But let’s not stop there.\u00a0 I’ve got a vector point layer of the Timeball location so I’ll add that and make it a 3D symbol\u00a0 I get yet a different Add Data window:<\/p>\n

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Ticking the first box sentences to point to always be a flat, two-dimensional image.\u00a0 Who wants that?\u00a0 Ticking “Display features as 3D vectors” is much more interesting, though it does look a bit horrendous when first added – anyone reminded of Google?:<\/p>\n

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We can play around with this to get a better result by going to the point layer’s symbology tab.\u00a0 When you click on the Symbol image you get the Symbol Selector:<\/p>\n

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No shortage of choices here but let’s get a bit more sophisticated.\u00a0 Click “Style References” and tick “3D Industrial”:<\/p>\n

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Back in the Symbol Selector, scroll down and you’ll see a range of industrial type building.\u00a0 There won’t be an image for the Lyttelton Timeball so we’ll just pick something similar for demonstration purpose:<\/p>\n

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And click OK:<\/p>\n

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We can tweak the symbol settings to get it scaled to its actual size and placement but this is probably pretty good for now.\u00a0 Because we’re zoomed in so far, the raster cells look at bit hazy, but that could be fixed with a bit more tweaking.<\/p>\n

So we’ve covered ArcGlobe as an alternative to ArcScene for 3D visualisations.\u00a0 It’s a little bit harder to use but I would argue gives better results especially for large areas.\u00a0 Have a 3D go next time you’re needing something like this.<\/p>\n

C<\/p>\n

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  \t<\/p>\n","protected":false},"excerpt":{"rendered":"

In this post we look at how to use ArcGlobe for 3D visualisations of large areas. One benefit of using GIS is the creation of 3D visualisations using geographic data.\u00a0 Often we can use ArcScene to do this, but it doesn’t take long to butt up against its limitations (speed, quality of display, fiddle-iness…), so […]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-2086","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/blogs.lincoln.ac.nz\/gis\/wp-json\/wp\/v2\/posts\/2086","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.lincoln.ac.nz\/gis\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.lincoln.ac.nz\/gis\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.lincoln.ac.nz\/gis\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.lincoln.ac.nz\/gis\/wp-json\/wp\/v2\/comments?post=2086"}],"version-history":[{"count":0,"href":"https:\/\/blogs.lincoln.ac.nz\/gis\/wp-json\/wp\/v2\/posts\/2086\/revisions"}],"wp:attachment":[{"href":"https:\/\/blogs.lincoln.ac.nz\/gis\/wp-json\/wp\/v2\/media?parent=2086"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.lincoln.ac.nz\/gis\/wp-json\/wp\/v2\/categories?post=2086"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.lincoln.ac.nz\/gis\/wp-json\/wp\/v2\/tags?post=2086"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}