Site Extraction with and Dynamo

By now, most people in the industry would have heard of, a spin-off from X (formerly Google X). Recently, updated their site extraction tool which pulls data from free open source datasets, Open Street Map and NASA. When combining with Dynamo, it couldn’t be any simpler to pull in topography information to your Revit model.

So how do we get started with this new-fangled technology?

Firstly, you’ll need a account. Once you have that sorted head on over to Once there you’ll be greeted with a Google map where you can search for your location. The map system works exactly as you expect it to. Simply drag and resize the selection box around the area you’re interested in and then select what you want from the menu on the top right of your screen.

When your data is ready, you can open it in flux and review the results. You simply drag and drop your keys from the column on the left into the space on the right. You can pan, zoom and rotate your way around the the 3D preview although as someone that works in Revit and Navisworks all day long I found that the controls aren’t the easiest.

Struggling with the navigation?
right mouse button = pan
left mouse button = orbit
scroll button = zoom

So all of this is great, but how do you get this into Revit? It’s actually incredibly simple.

You will need to have both Dynamo and the plugin suite installed, but once you have those installed you’re only a few minutes away from generating a Revit topography.

To get started you will need to login to through Revit and Dynamo, if it’s your first time using you might have to approve the connection between Revit/Dynamo and flux similar to what you would when sharing account information with online services and Google or Facebook.

Find the Flux package within Dynamo and first drop in the Flux Project node.

Once you have your flux project selected, it’s just three more nodes. Drop in the Receive from Flux node and select topographic mesh from the drop down. From there push the flux topography into Mesh.VertexPositions and then finally into Topography.ByPoints

Comparing the flux topography in red against the professional survey in blue, we can see that the flux topography is no replacement for a real survey, we are looking at a 5-8m difference between the survey and the flux data. Thankfully, surveyors aren’t going to be out of the job any time soon. This is the case on the example site in Sydney only though, other sites are far more accurate depending on where the source data is coming from. Remember the flux data is coming from a combination of sources including survey from satellites which leads to varying levels of accuracy. You shouldn’t rely on open source data like this as your sole source of information. You should be referring to relevant site survey information to verify the data against.

The inaccuracy of the data though doesn’t mean that the flux data is useless. Provided that you’re able to reference the flux data with known survey data and adjust to suit, this provides an excellent opportunity for using the flux data to fill in missing information surrounding your known survey and site. You then have opportunity to use the data for visualisation in concept stages or flyover presentations of large sites or precincts.


4 thoughts on “Site Extraction with and Dynamo

  1. Elk is a free plugin for Grasshopper that does the same thing. You can then bring that into revit via one of many plugins.

  2. Thanks! This is my favorite of this week. Works 100%.

  3. avatar Ecalzavara says:

    Noooo, and now that are shutting down? Do you know any similar service/webpage?? I discovered it only now but apparently they’ve suspended the registration to their services….

  4. avatar Ryan Lenihan says:

    there is an addin on the appstore called cad2earth. i’ll be honest, i’ve not had alot of luck with the addin, but other people swear by it. link to the addin: cad2earth revit addin

    i know it costs money, but something that i’ve been playing with lately is infraworks. from my testing it seems to pull in the same data as what flux does. an advantage of infraworks is that it pulls in the imagery as well automatically.

    the first part of this video i put together is the same site i posted about, but it’s using the infraworks model imported into navisworks.

    Prince of Wales

    if you’re using one of the architecture and engineering industry subscription you should already have infraworks available.

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