GS1452: Using the Power of AIMS and AutoCAD Map 3D to Manage Assets and Facilities

It turns out the presentation that one of our major clients presented at Autodesk University 2013 was also recorded as well.

If you have a registered AU account, you can watch the presentation online here.

Going to Autodesk University?

Well I'm not going unfortunately. But one of our major clients is.

Recep Alakus from Hume City Council will be at Autodesk University 2013 to present about using AIMS and AutoCAD Map3D to manage assets and facilities.

Most of our MapGuide-related handiwork is in use at Hume City Council. So this presentation may be of interest to any of you that are going to AU.

We can do that with MapGuide too! (or: Turning features into 3d charts)

I haven't been in the Autodesk partner game for quite some time now, so my knowledge about their commercial products (besides AIMS) have atrophied somewhat over time. Nevertheless I do keep in touch with the Autodesk blogosphere, and one particular blog post today caught my attention.

The reason it caught my eye, is that it turns out we can do pretty much the same thing in MapGuide through the combination of Google Earth and MapGuide's KML support. For this to work, you will need the recently released 2.4 version of MapGuide Open Source, as that contains some important KML-related fixes. This post will use the Sheboygan dataset to demonstrate this.

Here's the Sheboygan Parcels layer in Maestro

Notice the KML Elevation button. It is disabled because the Layer Definition is based on an XML schema that pre-dates KML support. So to enable it, just upgrade the resource to the latest supported schema version. Clicking on the KML elevation button gives you this dialog

This dialog has 4 simple settings:

• The Z offset: Defines the vertical offset distance
• The Z extrusion: Defines the associated "height" of each feature
• The Z offset type: Defines how to apply Z offset distance
• The units: Defines what units to interpret the Z extrusion as

So for example, if we wanted to "chart" the land value of each parcel, we'd apply the settings like so:

1. Enable the elevation/extrusion settings

2. Click the [...] button beside the Z Extrustion to bring up the FDO expression editor

3. The Z extrusion can be any FDO expression that evaluates to a number, so we put in the land value (RLANDVC), but for practical display purposes inside Google Earth, we divide this value by 1000. Because if we used the default elevation units of "Meters", a million-dollar parcel of land will extrude into Low Earth Orbit :D

4. For Z offset type, we can leave this unchanged. You only want to use Absolute if you want the extrusion to be interpreted from sea-level. But since Sheboygan looks to be a pretty flat area, we'll leave it as RelativeToGround

5. Finally the units we'll keep as-is

The only other thing we'll change is the scale range back to the default of [0 to Infinity]. From my experience, Google Earth has a bit of trouble zooming to the region if the layer's constricted to a discrete scale range.

Also we'll change the layer's tooltip to also show the land value (RLANDVC). Notice the use of the refined concat expression eliminating the need to construct what I like to call "concat pyramids" in the past.

Layer Definition tooltips are transformed into popups when you select such features in Google Earth.

Once that's done save the layer definition and then house it within a Map Definition. We do this so that the Map Definition acts as a "funnel" into the WGS84 coordinate system (which features must be in for them to properly line up in Google Earth), any non-WGS84 layers we add will be automatically re-projected to WGS84 via MapGuide's powerful coordinate transformation facilities.

Once it's been housed within a Map Definition. We can invoke GetMapKml on the Map Definition through the mapagent to produce a KML document for that map. Opening the KML document in Google Earth and clicking the Parcels node, takes you to that familiar region

Which you'll notice is not as flat as the data you're used to seeing :) Because these parcels have now been extruded based on the FDO expression we've provided earlier (RLANDVC / 1000). Notice how dividing by 1000 has indeed capped the extrusion to a reasonable level for display purposes. 

And if we tilt the view a bit, we can get a better view of the land value.

And if we select the tallest feature there, we find out that Leon B is sitting on a gold mine and that in general, land owners under Voting District 4 are filthy rich :)

The popup content is the same content that would be in a MapGuide tooltip if we were looking at this data via the normal AJAX viewer.

One thing to keep in mind here is that the KML support in MapGuide is still somewhat basic. There isn't much ability to fine-grain control the KML content that gets generated by MapGuide. If you have such requirements, you are better off serving KML from the GeoREST extension for MapGuide instead.

Speaking of which, we could certainly do with a 2.4-compatible release of GeoREST

Taking MapGuide beyond the Server and Web right into your desktop

Previously, I briefly mentioned how the new Local Connection mode in the next release of Maestro was backed by a new desktop implementation of the MapGuide API. This (lengthy) post covers this

Preface

Let's start with a little personal backstory of mine.

Remember this software?

The MapGuide ActiveX viewer (source: Directions Magazine)

Now truth be told. I was not a major fan of Autodesk MapGuide 6.5. I guess that could be attributed to the following:

• I was just getting started not only with Autodesk products and technologies, but also on the basic concepts, practices and workflows of GIS systems. So for all intents and purposes, I was a total noob at the time.
• Windows only. Ewwwwww!
• The viewer is an ActiveX control that can only be embedded in Internet Explorer. Ewwwwwww!

Now the first time I got acquainted with MapGuide was in 2005 with the 6.5 version. It was also the time at my first ADN event when I heard about Autodesk's next version of MapGuide. Seeing the demos of this next version in action was quite a mind-blowing experience, given my not-so-positive experience with MapGuide 6.x. 

The AJAX-based viewer, multi-platform support, purty looking maps, flexible data access through this mysterious (at the time, to me) FDO technology and the list goes on. It just ticked all the boxes of what a modern, open-ended web mapping system should be. But then came the biggest bomb-shell of them all: It will all be open source!* So then several months later, the very first version of MapGuide Open Source was released and the rest (as they say) was history.^


Now despite my less-than-flattering opinion about MapGuide 6.x. It did have some very unique qualities to it that has yet to be replicated in MGOS/AIMS. Its map viewer, due to being based on ActiveX meant it could be embedded into .net applications. The second quality was that MWF files can contain static layers. This combination meant that it was possible to build mobile and disconnected MapGuide applications in .net or any other windows technology that supports COM (Component Object Model)


And it is in this respect that MGOS/AIMS has nothing comparable in its technological offerings.

• Disconnected? Not a chance! Client applications must be connected at all times. No server connectivity = no maps for you! Even the latest mobile extension for AIMS still requires constant connectivity.
• Mobility? You could have a full blown MGOS/AIMS installation on localhost, which your windows application can communicate via an embedded Internet Explorer. A functional, but very inelegant configuration. Nothing approaches the simplicity of a windows application + static MWF + 3mb ActiveX control configuration that was possible with MapGuide 6.x

So while MGOS/AIMS does most things leaps and bounds better than MapGuide 6.x, there are some other things where it pales in comparison.


Enter the MapGuide Desktop API (hereby known as mg-desktop for the rest of this post). mg-desktop is a desktop implementation of the MapGuide Platform API allowing for the same feature data access, map rendering/stylization functionality as the MapGuide Server, but without needing a MapGuide Server installed on your machine!


Genesis


The seeds of the MapGuide Desktop API were planted with this groundbreaking AU 2009 presentation. This presentation, for those unable to access that link showed how MapGuide Open Source actually has lots of shared components that can actually be re-used outside of the MapGuide Server and Web tiers. 

The main example from that presentation was a simple snapshot application that can produce a rendered map image or DWF file from a list of named Layer Definition documents without ever needing to contact a MapGuide Server ever! The first thought I had after seeing that presentation, was simply: Can't we just use a Map Definition to drive all this?


The second thought was, that AutoCAD Map already proved that the MapGuide API can be taken in a different direction, away from the MapGuide Server/Web Tier to become a API inside AutoCAD Map

So couldn't we have another implementation that makes it a fully self-contained framework that is usable by any desktop application, taking the concepts proven feasible by that AU presentation to its logical conclusion? mg-desktop is my answer to that question.

mg-desktop is a desktop implementation of the Geospatial Platform API, with its own implementation of the core platform classes, as shown below:

Where the MapGuide API operates in the context of the MapGuide Server/Web Tier and the AutoCAD Map Platform API operates in the context of inside AutoCAD Map, mg-desktop operates in a standalone context, with no dependencies on any particular application. It provides a suitable foundation for creating your own desktop-based MapGuide application.

In addition to implementing the core classes and services of the Geospatial Platform API, it also includes some of the additional service APIs provided by the MapGuide API, such as:

• MgRenderingService
• MgDrawingService
• MgTileService

mg-desktop also supports loading of MapGuide Packages (*.mgp). So you can transfer data and resources from a MapGuide Server to an mg-desktop installation.

Key Differences from the MapGuide API

Because mg-desktop is a desktop implementation of the Geospatial Platform API, some concepts which were applicable in MapGuide and/or AutoCAD Map no longer apply in mg-desktop:

• There is no session expiry :D Session resources still exist as a way to have temporary resources
• There is no resource security model
• On the same subject, there is no authentication required for access to services.
• There is no need to open/save runtime map state. Everything operates off of the current state of the runtime map in memory.

The mg-desktop implementation of MgResourceService wraps a pre-defined directory on the file system. Folders and resources in the mg-desktop repository conceptually map to files and folders in the file system.


The mg-desktop implementation of MgFeatureService is a thin wrapper around FDO. Each service API maps to a corresponding FDO command. All FDO types that would be returned are wrapped up and/or converted to their corresponding Mg* counterparts.


Aside from these differences, it's the same MapGuide API that you've come to know all along.

Unique APIs


mg-desktop not only just implements the abstract classes in the Geospatial Platform API, but extends them with our own additional APIs to correct my perceived shortcomings of the current MapGuide APIs. Here's an overview of the unique APIs of mg-desktop.


MgdFeatureService


MgdFeatureService is the desktop implementation of MgFeatureService and includes the following extra methods:

• RegisterProvider - Registers a new FDO provider into the provider registry by its library path
• UnregisterProvider - Removes a registered FDO provider from the provider registry by its provider name
• InsertFeatures - Allows for individual insertion of features into a feature class, instead of having to use the monolithic UpdateFeatures
• DeleteFeatures - Allows for individual deletion of features in a feature class, instead of having to use the monolithic UpdateFeatures
• UpdateFeatures - Although it unfortunately shares the same name as the monolithic method it's trying to replace, this allows for individual updates of features in a feature class.
• SelectFeaturesExtended - Almost identical to SelectFeatures, except this returns a scrollable feature reader that behaves similarly to the FDO scrollable feature reader

MgdLayer


MgdLayer is the desktop implementation of MgLayerBase which adds extra convenience methods, allowing you to operate on the layer itself instead of needing to obtain an MgFeatureService reference and the layer's feature source id and class name:

• BeginTransaction - Convenience form of MgFeatureService.BeginTransaction
• SelectFeaturesExtended - Convenience form of MgdFeatureService.SelectFeaturesExtended
• InsertFeatures - Convenience form of MgdFeatureService.InsertFeatures
• DeleteFeatures - Convenience form of MgdFeatureService.DeleteFeatures
• UpdateFeatures - Convenience form of MgdFeatureService.UpdateFeatures

The Map Viewer Component


So having a reusable library to build your own geospatial applications is good and all, but is there something out-of-the-box like a map viewer that we can embed in a .net application? The answer is an emphatic yes. mg-desktop includes an embeddable map viewer component!

This is not some trick of embedding a web browser to use the AJAX viewer to talk to a local or remote MapGuide Server, this is all native .net WinForms controls and using the same self-contained MapGuide rendering and stylization services provided by the mg-desktop library and it does pretty much everything you can do in the AJAX/Fusion viewer.

What about more complex stuff like digitizing and redlining? No problem. It can do that too!

And all of this is functionality is contained in one single sub-100kb dll! (OSGeo.MapGuide.Viewer.dll). The next release of Maestro will be using this viewer component for previewing Feature Sources, Layer Defintions, Watermarks and Map Definitions in the new Local Connection mode

In Closing...


I have submitted a pending RFC to have this included in the official MapGuide source tree, which would greatly improve integration, code re-use and ability to receive fixes and enhancements to upstream components.


The source and binaries# for the mg-desktop library (and map viewer) are available from the Google Code project home page. Note that FDO that is included with the binaries is a partial distribution (because I lack the ability to build certain FDO providers). You will need a Mercurial client to checkout the source code.

If you want to build the source, you will need to do a full svn checkout of MapGuide Open Source and FDO trunk. Then you will need to build FDO and the MapGuide Oem components first before you can finally build mg-desktop. The hg clone needs to reside in a Desktop subdirectory under MgDev in your MapGuide svn working copy. There is currently no 64-bit or Linux targets yet, so feel free to submit any patches.


* Let's give credit where it's due here. mg-desktop, Maestro and FDO Toolbox would not exist if it weren't for Autodesk open sourcing the MapGuide product and FDO technology. Similarly, my knowledge of MapGuide and FDO wouldn't have reached encyclopedic levels that they are today if these technologies were not open sourced.

^ As most of us found out, v1.0.0 of MapGuide Open Source turned out to be pretty rough round the edges and performance of Feature Joins (which 6.x handled brilliantly) was absolutely woeful and buggy, which sadly is still applicable to this very day. But this is a known problem with a known workaround, which is to have all the data in a centralised, spatially-enabled RDBMS, which you should be already doing in the first place.


# To reduce download size, mg-desktop contains a reduced distribution of CS-Map. If there are problems due to missing coordinate systems, download the country-specific grid files here and drop them into the Dictionaries directory.

An interesting find

This is the root directory of the Autodesk MapGuide Enterprise 2011 install image



Let's take a look inside...


Either this was included to satisfy open source licensing requirements (IANAL) OR it makes building MGE-compatible extensions much easier

What do you think?

An interesting AU session on the internals of MapGuide

Though I didn't go to Autodesk University in person or virtually (maybe I will one day), I'm always interested in checking out the Geospatial-focused sessions that have been posted online. This year, there seemed to be the usual lot of sessions introducing MapGuide/FDO/Map3D, but one particular session caught my eye of interest:

http://au.autodesk.com/?nd=class&session_id=5241

This session is particularly special because at face value, it is not introductory in any way. You are assumed to know about what MapGuide and FDO are about. The session goes through the internals of MapGuide and demonstrates an example of using MapGuide in a standalone context (no server tier, no web tier).

This is a one of a kind presentation. I recommend checking out the slides/sample/podcast. It has certainly opened my eyes to the possibilities!