Using a DXF to Locate a Point Cloud in Revit with Very Large Coordinates

I thought that most of this was ‘easy’ and solved now, but it was more of a challenge than I expected. I received a ASC file from a survey in XYZRGB format, which looks like this:

Those XYZ values are Metres (or Meters if you are in US) in the MGA 94 coordinate system. I also received a DXF file with the same World coordinates, and project related gridlines so I could relate the point cloud to our Revit models.

I tried getting the MGA Shared Coordinates right in Revit, and then linking an RCP or RCS from Recap ‘by Shared Coordinates’, but I didn’t have much joy.

Here is the workflow that worked for me…

Getting the right Shared Coordinates in Revit

1. Start a new, blank Revit model
2. Link the DXF Centre-to-Centre (this is best way to deal with huge coordinates)
3. Acquire Coordinates from it
4. Save your Revit file. You now have the right World coordinates, and a project grid relationship.

Importing the Point Cloud by Shared Coordinates 

1. Open Recap and import the data. For the ASC data above, on the…

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