Add 3D Model with Real Coordinates

There are a wide variety of 3D Models that can be added as data sources in InfraWorks. The options for 3D Models Files are .3ds, .dae, .dxf, .fbx, and .obj. With the right version you can also add IMX, Revit, IFC, and LandXML files as well. But for this post, I am going to be working with .fbx files exported from Revit.

iw_3d_exportFBX is a 3D exchange format that can be used and generated by a variety of programs and tools. In Revit, FBX is towards the top of the Export menu.

Like with any 3D export, you want to make sure you are in a 3D view. Unlike with DWG or IFC export, there are not many settings to be adjusted.

The only options (once in the export dialogue) are Use LOD and Without boundary edge.

iw_3d_export options

I don’t have much experience with using either of these options, but according to a Revit to Unity Workflow pdf by Penn State:

“With “Use LOD” ON you will get a more faceted model, but a smaller file size. If LOD is OFF, your model will be smoother and more true to ‘actual geometry’ but the file size will be much bigger, and exporting time will be longer.”

“When “Without Boundary Edge” is turned ON, you will not see the lines that appear wherever two surfaces come together. This provides a less ‘mesh’ like model […] and thus has a less ‘constructed’ look to it – appearing more as it would in real life.”

Also, it is important to note that the Project Base Point will export as the origin for the fbx file. Once in InfraWorks, you will need to know the real world coordinates for this point.

iw_3d_front revit

If you have your Survey Point and Project Base Point in the same x,y position and have already Specified Coordinates based on a survey file, then you will need those Northing and Easting coordinates on hand. If not, you will need to find out the Northing and Easting (x,y) of your Project Base Point relative to your survey file.

Now, you will also need to know the Coordinate System of your survey file (or other coordinate-based file). In the United States, surveys are done in the State Plane Coordinate System, but you just need to know the right coordinate system.

iw_3d_initialOnce you have exported to fbx, add it into your InfraWorks file. Like all data that is not yet configured, it will appear at the top of Data Sources. Right click it to configure.

If you check the 3D Model tab, you can see that the model origin is in the same place as the Project Base Point in Revit. So far, so good.

iw_3d_front iw

But the important information is on the Geo Location tab. First, you want to make sure your main Coordinate System is set to an Arbitrary coordinate system with correct units.

iw_3d_geo location

For some reason it must be Arbitrary to allow for the Position Coordinate System to be modified. XY-IFT is an Arbitrary X-Y, but it is in Feet, which is what I want.

iw_3d_coordinates ft

From there, you have two options, Specify the Position or Interactive Placing. If you do not have Northing and Easting data and/or you do not know the Coordinate System where that data comes from, you can use Interactive Placing. But using the Position is much quicker and more accurate.

The second Coordinate System (under Position), is where you need to enter the actual survey coordinate system.

iw_3d_coordinate system

iw_3d_northing eastingThen enter (or copy/paste) the Northing (X) and Easting (Y), while using the Local Origin. The Z should remain empty.

You want to be sure that you do not enter these under the Offset X and Y, since this will actually move the origin of the 3D Model.

Close & Refresh, and the 3D Model should now be correctly placed within InfraWorks.

iw_3d_finalBut as you can see, the results aren’t always perfect. My 3D Model is actually floating slightly above the Terrain (and my Terrain data has a slight gap). Though you can adjust for discrepancies, this is one of the downsides to merging less accurate GIS data with more accurate data.


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