Geolocation is the process of assigning a real-world position to a digital model. It ensures that a model created in CAD or BIM software can be accurately placed within its surrounding environment, aligned with existing buildings, terrain and other spatial datasets.

Accurate geolocation is essential when working with models in a wider spatial context. It allows projects to be visualised, coordinated and analysed within their real-world environment.

The model’s location can be defined in two ways: either by embedding positioning information within the model itself, or by supplying the coordinates separately during import.

Geolocation workflows

Zeroed models

A zeroed model has a known reference point (for example, a building corner, survey point or project origin) positioned at 0,0,0 within the modelling software. The real-world coordinates for this reference point are then provided separately during import.

This is the recommended workflow for VU.CITY. Keeping the model geometry close to the modelling origin helps minimise potential precision issues and provides a consistent approach across different modelling software and export formats.

Using reference object (VU.Origin)

For workflows where moving the entire model to the modelling origin is not practical, VU.Origin provides a way to define the model’s reference point and orientation without modifying the model geometry. Instead of moving the model to 0,0,0, the VU.Origin object can be placed at a known reference point within the model or modelling space. The model remains in its existing position, while VU.Origin acts as the model’s origin reference during import.

The VU.Origin reference point can be used in two ways:

• As a local origin - when no coordinate information is provided, VU.Compass defines the model’s reference point within the imported file.
• With real-world coordinates - when the object is named using the provided naming convention
  • (example: VuOrigin_27700_529139.000_181682.050_50 )
    the embedded coordinates are used to position the model accurately within the VU.CITY 3D app.
    

VU.Compass workflow

1. Place the VU.Origin object at the required reference point.
2. Rotate VU.Origin so that its north direction aligns with true north.
3. If supported by your modelling software, rename the object using the VU.CITY naming convention VuOrigin_CRS(EPSG)_CoordX(m)_CoordY(m)_ElevationOffset(m).
4. Export the model with the VU.Origin object included.
   

During import, VU.CITY reads the VU.Origin reference point and, where available, uses the coordinate information to position the model automatically.

The VU.Origin workflow is particularly useful when:

• the model has already been created using project coordinates;
• moving geometry to the modelling origin would disrupt existing BIM/CAD workflows;
• multiple models need to maintain a shared reference point.

VU.Origin does not replace the need for accurate coordinate information. It provides a consistent way of transferring model positioning information alongside the geometry.

Geolocated models

A geolocated model contains real-world positioning information within the file. Depending on the software and export format, this may include:

• Coordinate Reference System (CRS)
• Easting and Northing
• Elevation
• Orientation

While this approach can be useful where accurate positioning information is already embedded within the source model, exported visualisation formats may not retain the full coordinate context from the original CAD/BIM file.