AGOL scenes default to using the Web Mercator spatial reference system, with all default background map content also conforming to that. Unfortunately, the subsequent mixing of layers with differing spatial reference configurations is not supported. As such, any default background maps will be removed if, say, a mesh in EPSG:27700 (British National Grid) is introduced alongside. This behaviour contrasts to what can be expected when working inside ArcGIS Pro.

It is possible to re-project an EPSG:27700 integrated mesh into Web Mercator, using the ‘Project’ geoprocessing tool found in ArcGIS Pro. Although this might take a notable amount of processing time to accomplish, the output will potentially be able to sit alongside any ArcGIS Online background content. If taking this route, you’ll obviously need to re-project any other data layer that you’re planning to use before introducing them into the AGOL environment. In most situations, it's going to be impractical and ineffective to apply the default background mapping within your project.

Navigating the scene

Scene navigation, within the Scene Viewer, is standard regardless of content. The middle mouse button controls the zoom extent, whilst the left and right mouse buttons, in conjunction with mouse movement, control panning and rotation. When applicable, clicking a distinct feature, within the current view, will open a pop-up menu showing relevant attribution.

On the top-right of the UI, buttons enabling several further tools can be found. These include options for further adjusting the scene’s appearance, via the use of real-time daylight and weather data.

Working with additional geospatial vector layers

While your users may be happy just to view a raw OS 3D mesh, it’s more probable that you’ll want to combine this with other data sources to create your own unique narrative. Geospatial vector layers are an obvious source of additional detail, so we’ll cover this in detail in the following pages.

The method for adding vector layers is no different from how you would add a mesh – you just choose what you need from your Content repository. Assuming everything is working correctly, these layers will then be added into your scene in the same manner.

It’s normal for analytical tasks, such as line-of-sight calculations, to be undertaken in a desktop GIS environment, rather than a web environment like AGOL. However, AGOL is certainly a platform that can be effective at sharing the results of such analysis, particularly in the context of an ESRI Story Map.

ESRI Story Maps, along with the other AGOL tools, allow the inclusion of 3D Scene components…which therefore supports interactive usage of OS 3D Mesh data. There’s clearly a lot of creative potential present here. How you choose to utilise this is up to you!

Once your data layers have been uploaded and are ready for use, you’ll then need to commence with the creation of your project. ESRI offers some interesting options (for example, Story Maps), but the simplest choice will be to create a 3D scene that will be accessed from with the Scene Viewer tool.

There are several ways to achieve this, but the most obvious is to navigate to the Scene page (via the top menu), then press the [+] button that’s found on the top menu. Here, you’ll be asked to choose between creating a ‘Global’ or ‘Local’ scene. Global scenes are based around a full globe model, whilst a Local scene will offer a more typical 3D environment. By default, ESRI provides a default background map layer for both options. If you’re going to be working with OS mesh data, the ‘Local’ scene option is likely going to be more appropriate.

In ArcGIS Pro, any layer dragged into the ‘2D Layers’ section in a Scene will automatically be draped across a suitable ‘surface’. Meanwhile, layers within the ‘3D Layers’ section will be rendered according to their full 3D geometry.

In AGOL, however, things are handled slightly differently. Here, there is no need to place the layer under a particular heading. Instead, styling/rendering behaviour will be defined by choices made within the ‘Layer style’ and ‘Layer properties’ panels. Of these, ‘Layer style’ defines the core rendering options.

To access the ‘Layer style’ panel, the Layer Manager panel first needs to be selected from the side bar, as shown:

Each listed layer will have further options that will be exposed via the ellipsis ( ‘…’) icon. ‘Layer style’ can be found at the top of this list.

Selecting ‘Layer style’ should then open this interface:

The ‘Layer style’ panel will typically include an option relating to attribute-based classification, along with several ‘drawing style’ choices. Each of these choices, once selected, will then reveal a further set of options and settings.

Content page

The AGOL ‘Content’ page is the primary means for building and viewing the collection of resources that you are going to be using in your project. This includes any OS 3D mesh objects you might be wishing to work with. Data layers can be added in to your Content page in a few distinct ways. If you already have data within ArcGIS Pro, you can copy that into AGOL. Alternatively, data can be uploaded from your local machine, or from cloud services like Dropbox or OneDrive. Web service links are also supported. The ‘New Item’ button, found in the Content page, is used to access most of these options.

Adding layers from ArcGIS Pro

If data is already present in an ArcGIS Pro project, you can push this into your AGOL environment from within ArcGIS Pro itself. To achieve this, open your ArcGIS Pro project and select the layer you wish to use within the Contents pane. Then, right-click the layer and select Sharing -> Share As Web Layer, as shown below:

Upon doing this, a ‘Share as Web Layer’ window should become visible. Here, descriptive details about the layer can be entered. These will then be made present in the online content.

This tool also includes an ‘Analyze’ function, which checks that the layer is suitable for inclusion within the Online space. A common reason for this to fail is when ‘Unique numeric IDs are not defined’. To solve this, right-click the error message and select ‘Auto-Assign IDs Sequentially’.

To continue with the upload, use the ‘Publish’ button.

On completion of the upload, the layer should then be listed within AGOL’s Content page. That screen should then look something like this:

OS meshes can be incorporated in AGOL and used within the various tools and templates that are offered. Further to this, additional data layers can be incorporated alongside, enabling the creation of unique and engaging content. It’s a great way of sharing mesh data to a wider audience.

Whilst AGOL contains a lot of functionality, it probably shouldn’t be viewed as a stand-alone solution. Instead, it’s typically used in conjunction with a separate desktop GIS application (ArcGIS Pro, etc.), with such tools typically being used for data preparation. This aspect isn’t covered in this document, as it’s assumed that you’ll already have your own methods and preferences for such activities.

The output from AGOL projects can be a basic view of the data using the Scene Viewer tool. However, more specialist options, such as ESRI Story Maps or Experience Builder, can also be configured to use mesh-orientated scenes.

Accessing ArcGIS Online

AGOL is accessed by visiting Account Login - ArcGIS Online and following the sign-on process that’s relevant to your specific account. Once successfully logged in, you’ll see the AGOL homepage, which will include a top menu bar that looks something like this:

The options listed on this menu link to the most commonly used AGOL tools. However, an additional ‘waffle’ menu (i.e. nine dots in a square) grants access to an extended set of options. For the purposes of these instructions, where an integrated mesh is the primary subject of interest, we’ll primarily work within the Scene Viewer, additionally using the Content page to manage our resources.

Index

The topics covered in this guide are listed below:

• Adding data to AGOL

• Creating a 3D scene

• Adding an OS Mesh

• Spatial reference systems

• Defining 'Layer Style' options

• Polygon layers

• Line layers

• Point layers

• Text labels

• Custom 3D models

• Spatial analysis and reporting

An additional, more advanced, AGOL feature involves placing custom 3D models within a 3D scene. Incorporating such models alongside an OS mesh offers a lot of scope for creativity and interest. This could be particularly effective, should you wish to demonstrate how a new building or structure might fit in, visually, with existing surroundings.

Many tools are available that allow you to create whatever 3D model you need. Blender, for example, is a popular open-source choice that can work well for this. Alternatively, repositories of pre-made models are available online, should a stock model be sufficient for your requirements.

Unfortunately, it’s not currently possible to add a 3D model directly into the AGOL Content area. Instead, an ESRI-specific ‘3D Object’ feature type needs to be prepared, within ArcGIS Pro, as a preliminary step. This ESRI tutorial - Import and incorporate 3D models in a scene | Documentation - covers this well. Once the model has been prepared and exists as an ArcGIS Pro layer, it can then be ‘shared to web’ (left-click the layer and select ‘Share As Web Layer’…), thus copying it directly into your AGOL Content store.

Object Creation Hints

When creating a 3D asset, it’s usually good practice to locate each object’s origin towards the bottom of the model. If using Blender, it’s also advisable to apply any rotation and scaling, along with any active modifiers, before export. Also, if you’ve used any advanced procedural shading tools, you’ll need to bake those into a texture.

Finally, upon export, the suggested 3D file format is .glTF/.glb. This is a good option, as it’s able to pack textures within the file, making it straightforward to manage.

Line feature layers can be added into an AGOL scene by, again, first adding them into your Content area, then selecting them from within the Scene Viewer interface using the ‘+’ button.

Line feature layers have their own unique options within the ‘Layer types’ pane. The options offered will be dependent upon whether the line feature layer, itself, has been supplied with a 2D or 3D geometry.

If you’re working with 2D data, the available ‘Layer type’ options should look like this:

Alternatively, if you’re working with a 3D line layer, you should instead see these options:

Examples of each option are thus described below.

‘2D Types’ (for 2D layers only)

The ‘2D Types’ option renders the line features as 2D draped lines. When used alongside a mesh, it can be an effective solution when viewed from afar. However, as the following figures show, it can look rather odd when viewed close-up.

If using this mode, it’s certainly worth experimenting with different line widths, as it’s often easy for detail to be lost amongst the complexity of a 3D mesh.

‘3D Types’ (for 2D layers only)

The ‘3D Types’ option will render line features as a solid geometry. By default, this will be realised as a set of ‘tubes’, but different shapes are available, should you prefer a rectangular or square profile. As with ‘2D Types’, there is also the option to specify different line widths.

The ‘3D Types’ option also undergoes a degree of mesh draping. However, for this option, the result seems to be much generalised in comparison. Thus, if viewed close-up, the ‘tubes’ may be seen to pass directly through a tree canopy, rather than conform to its outer edges:

‘2D Line’ (for 3D layers only)

In this option, line features will be rendered very simply, as if they were lines on a page, albeit in 3D space. As the supplied line layer will already contain its own height data, no attempt to drape the features will be made. As such, there will no direct dependency on the mesh, assuming one is present. This, of course, will eliminate the potentially unwanted behaviours discussed in the previous sections. However, there may, instead, be occasions where the line features dip below the mesh’s surface in ways that are not wanted.

‘3D Path’ (for 3D layers only)

Like the ‘3D Type’ option covered previously, this option will render lines as solid objects, using the shape profile of your choice. Again, because full 3D geometry is present, no draping is undertaken, with the vertical position relying entirely on the layer’s own geometry. This option can potentially solve the ‘below the surface’ issue mentioned above, with the line thickness making it more likely that the layer will remain fully visible.

The general functionality of point layers largely mirrors that of polygons and lines, detailed on the previous two pages. For points, the primary rendering options are ‘2D Marker’ or ‘3D Object’. Details of these options are included below.

‘2D Marker’

This mode displays each point as a 2D ‘billboard’ object. That is, the point representations will always rotate to face the user.

To select a shape, users can choose from a small selection of ‘Basic Shapes’ or a much larger selection of ‘Icon’ images. There’s also an option where a custom image can be uploaded. In addition, further styling options are available. If using such icons over a detailed mesh, care needs to be taken to ensure that they remain sufficiently visible.

‘3D Object’

Rather than use a 2D billboard, ‘3D Object’ mode allows a full 3D model to be used to represent each point. Many candidate objects are available, which have been classified across several different screens. A selection of these is shown below:

Unfortunately, there doesn’t seem to be an option to upload your own custom 3D models for use with this feature.

When using this option alongside a mesh, it’s very easy for the models to either get lost, or to dominate the scene out of all proportion. As such, a degree of caution is advised!

An option to include text labels, that relate to a given layer, can be found in the ‘Layer type’ options of polygon and point features. If this is enabled, a set of additional parameters is exposed. These allow you to specify which attribute you wish to base the labels on, as well as choose from some simple label styling options.

With a 3D scene successfully created, you’ll want to add your own content. For the purposes of this guide, we’ll assume that you’ll first want to add an OS 3D mesh.

To do this, choose the Browse Layers option, via the ‘+’ button on the side menu, to open the Browse Layers window. This will list your current repository of online content. From here, find the entry for your mesh and press the associated ‘Add +’ button.

The mesh will be now added into the 3D scene.

Polygon vector layers are typically easy to integrate, alongside a mesh. When working with such data, the main choices are ‘2D polygon’ and ‘3D Extrusion’. In addition to these, a third option, ‘Water’, enables animated water effects.

Alongside the ‘Layer style’ panel, the ‘Layer properties’ panel, selectable from the same pop-up list, is also available. This includes parameters for things like ‘transparency’, ‘elevation’ and ‘visibility range’.

Upon adding a polygon layer into a scene, it may initially be visualised using just some simple black outlines. If you’re working with a mesh, this can be a problem, as these lines can become hidden, making it appear that your layer has failed. Fortunately, this issue will resolve itself upon the selection of one of the ‘Layer style’ options. Alternatively, you can temporarily hide the mesh layer, using the eyeball icon, to obtain an unobstructed view.

Draping a simple polygon layer

A simple, unclassified, polygon layer can be effectively used to draw attention to significant areas within a mesh. The ‘2D Polygon’ option, from within the ‘Layer style’ panel, should be sufficient to achieve this. As can be seen in the following figure, adding a degree of transparency to that layer will likely prove effective.

Draping a categorised polygon layer

If you’re working with a set of categorised polygons, extending the previous method to make use of the ‘Choose the main attribute to visualise’ option can achieve worthwhile results. Choosing a suitable attribute from this drop-down list will automatically assign categorised colours to each polygon. However, these colour choices, along with other attributes, can be subsequently edited for each individual category from within the Options screen.

Again, in the following example, transparency has been adjusted to ensure that mesh detail is still easily visible.

As with all such vector layers, individual features can be selected by left-clicking on them. Any associated attribution is then displayed within a pop-up menu.

Finally, it should be noted that, upon selecting a categorisation attribute, AGOL removes the option to render the polygons as animated water.

Extruded draping with polygons

If the ‘3D Extrusion’ option is chosen from the ‘Layer style’ panel, the selected polygon layer will still be draped over your mesh. However, it will also be vertically extruded to form solid objects. Due to the erratic nature of mesh geometries, the result of this can often be unappealing, as is evident in the example below:

It seems probable that the ‘3D Extrusion’ option wasn’t created with mesh-based applications in mind. Instead, this is something that’s going to be more useful when directly working with building footprint data, perhaps in a more standard mapping environment.

Animated water extents

The third of the polygon-orientated ‘Layer style’ options is specific to the representation of water extents. When used alongside a mesh, this works in much the same way as the ‘2D Polygon’ option, in so far as it drapes the nominated polygon layer over the mesh surface. However, as the name implies, this option renders the polygons as an animated water surface. In an appropriate environment, this will include reflections of the surrounding scene. It’s a very nice effect.

To set up an effective water scene, you will likely need to adjust settings in both the ‘Layer style’ and ‘Layer properties’ panes. Specifically, if you should notice that the water polygon is not visible and that the layer name is ‘greyed out’, the Visibility Range parameter may need adjusting. Also, if you’re depicting rivers or lakes, it’s also likely that you’ll need to change the water’s colour to something more appropriate than the default bright blue!