How to Geolocate your model (or drawing) using a different EPSG code

If you need to geolocate your model or drawing, but cannot use the geocoordinate system that your project is in, you can follow the instructions below to achieve accurate geolocation. For Drawings, you only need to perform the stage of Converting from Source to Destination system, since you will have the numbers to begin with.

Note that this only applies when your project uses a cartesian coordinate system (uses Easting and Northing).

Terminology:

• Source EPSG System: The EPSG code of your project that you have the initial values for.
• Destination EPSG System: Use "4326 - WGS 84".

Getting the Source values

1. Load your model into your scene.
2. Open the transform side sheet (Move, or press M or T).
3. Change the dropdown to Project origin.
4. Ensure the Use custom coordinate system toggle is off.
5. Set the x and y values to 0 (while keeping the rotation values at 0 - we will adjust rotation later).
6. Change the dropdown back to Bounding box center.
7. Copy the X and Y values.

Converting from Source to Destination system

1. Go to epsg.io/transform
2. Set the Input coordinate system to your source EPSG system.
3. Set the Output coordinate system to your destination EPSG system.
4. Enter your copied X/Y values into the Input coordinates field.
5. Press Transform.
6. Click the Format button twice to change to decimal.
7. Copy the Longitude and Latitude values.

Entering the Destination values

1. Go to your model's transform side sheet.
2. Set the dropdown to Bounding box center.
3. Turn on the Use custom coordinate system toggle, and select your destination EPSG system.
4. Paste in the values you got from epsg.io.
5. You must then add a slight rotation value (this step is important and always required - see the next section).

Entering the Rotation value

This is due to the fact that a cartesian coordinate system is trying to wrap a 2D grid onto the surface of a sphere. Because of this, cartesian system's north do not perfectly line up with true north.

1. Go to your project's geocoordinate page.
2. Find your Source EPSG system, and copy the Angle to True North.
3. In the transform side sheet's Rotation Z field, subtract the Angle to True North (so if it was -0.434 in the Project's page, you will need to have 0.434 as the z-rotation value).
4. You are now complete. All other models you bring can be snapped to this model, so that you do not have to do this again.