Rhino, Revit and Shared Coordinates: keep coordination simple with BEAM

Shared Coordinates, Internal Origin, and Better Rhino–Revit Workflows

Location and coordinates are fundamental to every architectural or engineering model. They define where the project sits in space and how it relates to the real world.

To work efficiently, it helps to understand that a model usually involves two different coordinate concepts:

1. Internal Origin

Every CAD or BIM platform has one true geometric coordinate system used internally by the software.This is the system where all geometry is calculated using XYZ values from a single point: (0,0,0).

That point is often called the Internal Origin.

All objects in the model are mathematically defined relative to this origin. It is the coordinate system the software uses for calculations, geometry operations, snapping, scripts, exports, and precision.

There is only one internal geometric origin.

2. Shared Coordinates / World Coordinates

Projects also need to relate to the real world.

For that reason, software allows an additional coordinate reference system that defines how the internal model relates to site coordinates, survey data, GIS references, consultant files, or national grid systems.

This is commonly called:

• Shared Coordinates in Autodesk Revit

• Survey coordinates

• World Coordinate System (WCS) in some CAD tools

This system typically stores:

• Easting / Northing / Elevation

• Rotation to North

• Relationship between the model and real-world location

So rather than moving the building geometry to huge real-world coordinates, the model stays clean internally while another coordinate system defines where it belongs externally.

Shared Coordinates are simply offset and rotation values applied to the model’s local geometry coordinates to represent real-world position, keeping the actual geometry near the origin and therefore more stable and precise.

Why This Matters

A common mistake is placing project geometry directly at real-world coordinates.

For example, if the site coordinate is hundreds of thousands of metres from zero, the building may also be modelled there.

That creates problems because computers have limited numerical precision. When coordinate values become very large it will truncate values:

• curves may fail

• surfaces may contain tiny gaps

• modelling commands become unstable

• interoperability becomes unreliable

• scripts may fail

• display artifacts appear

This is especially noticeable in Rhino and other geometry-heavy workflows.

Our Recommendation

Never model in real-world coordinates. Keep the actual model geometry close to the internal origin. Use shared coordinates only as a reference layer between the model and the real world.

Best Practice for Project Setup

A practical workflow is:

Internal Origin

Place it in a logical modelling location, often near the project extents, such as a bottom-left corner outside the building footprint.

Benefits:

• coordinates remain small and positive

• geometry stays stable

• future project expansion does not cross axes

• modelling remains efficient

  
  

Shared Coordinates

Then define a survey point or shared coordinate system that says:

This real-world point is located here relative to the model.

If later the project moves 1 metre east, you usually adjust the shared coordinates instead of moving the whole building.

That keeps the geometry untouched and coordination simple.

In Revit, the model stays near the Internal Origin while Shared Coordinates define its real-world position and rotation.

Rhino keeps modelling near the Internal Origin while a Named CPlane stores the Shared Coordinates for coordination.

Revit and Rhino Comparison

In Revit

Autodesk Revit includes:

• Internal Origin

• Survey Point / Shared Coordinates

• Project Base Point (useful in some workflows, though often secondary)

  
  

In Rhino

Rhino uses:

• World Top CPlane as the internal modelling origin

• Named CPlanes as alternate coordinate systems

So in practice, a Named CPlane can represent shared coordinates.

Our Recommended Rhino–Revit Workflow

For daily modelling, we usually recommend:

Internal Origin → Internal Origin

Keep Rhino and Revit aligned using their internal modelling origins.

This gives stable files, cleaner geometry and easier exports/imports with fewer precision issue

But What If Shared Coordinates Are Required?

Sometimes projects are already established differently for various reasons:

• consultant models use site coordinates

• IFC files come from another internal origin

• project setup is already fixed

• multiple disciplines must align via survey coordinates

In those cases, shared coordinates still matter.

Existing Solution in BEAM

BEAM and RAY already support shared-coordinate workflows.

In Rhino, users could create a Named CPlane matching the Revit shared coordinate system, allowing proper alignment while modelling near origin.

This works well, but it requires manual setup and deeper coordinate knowledge.

New Improved Workflow

With version 1.14.4.2, BEAM extends this further with improved Revit → Rhino Shared Coordinates support, making coordination much easier while keeping modelling workflows clean.

How it works

1. In Revit, use RAY to export the model using Shared Coordinates.

2. In Rhino, use RAY to import that coordinate system as a Named CPlane.

3. When importing IFC files, consultant models, or external geometry, select that Named CPlane so incoming files land in the correct shared position.

4. Once coordination is complete, continue working in Rhino with normal local modelling coordinates close to origin, where performance and precision are best.

5. When geometry is sent back to Autodesk Revit through BEAM, the shared coordinate relationship is preserved.

   
   

The Result

You get the best of both systems:

• accurate coordination with consultants and IFC data

• stable Rhino files near origin

• easier navigation and cleaner modelling

• fewer precision issues

• no manual moving or guessing rotations

In short, you can coordinate in shared coordinates while continuing to design in local coordinates.

Simple workflow: export Shared Coordinates from Revit, create a Rhino CPlane, import external models correctly, then keep designing near origin.

RAY lets you export Shared Coordinates from Revit as part of the standard BEAM workflow.

Import IFC files in Rhino using the Shared Coordinates CPlane for correct project alignment.

BEAM transfers the Revit model into Rhino while preserving Shared Coordinates for accurate alignment.