IFC-Exporter-Rhino/README.md

Speckle → IFC 4.3 Exporter (Rhino)

A Speckle Automate function that converts Speckle models (from Rhino and other authoring tools) into IFC 4.3 files.

How It Works

1. Receives a Speckle model version via Speckle Automate.
2. Traverses the nested Collection tree to find all BIM elements.
3. Classifies each element into its IFC type (e.g. IfcColumn, IfcWall) using the Attributes.type property.
4. Exports geometry — meshes, instances (block definitions), and curves — into IFC representations.
5. Clones properties — attributes, property sets, and quantities — from the Speckle object onto the IFC entity.
6. Writes the resulting .ifc file.

Supported Property Formats

The exporter handles two property formats:

Nested (ArchiCAD / IFC-native)

Properties are stored as nested dicts under _properties:

_properties:
  Attributes:
    Name: "MyColumn"
    type: "IfcColumn"
  Property Sets:
    Pset_ColumnCommon:
      IsExternal: true
  Quantities:
    BaseQuantities:
      Height: {name: "Height", units: "millimetre", value: 3000}

Flat Dot-Notation (Rhino / Speckle)

Properties are stored as flat key-value pairs with dot-separated paths under properties:

properties:
  Attributes.Name: "600S162-43-50"
  Attributes.type: "IfcColumn"
  Attributes.GlobalId: "yOTS1rnOhBKW4JIfec29TS"
  Quantities.BaseQuantities.Gross Weight.value: "15.452"
  Quantities.BaseQuantities.Member Length.value: "118.938"

The exporter automatically detects the format and unflattens dot-notation keys into the nested structure before processing.

Function Inputs

Input	Description
file_name	Output IFC filename (timestamp is appended)
IFC_PROJECT_NAME	Name for the IfcProject entity
IFC_SITE_NAME	Name for the IfcSite entity
IFC_BUILDING_NAME	Name for the IfcBuilding entity

Project Structure

main.py                 # Automate entry point — traversal, export loop, IFC writing
utils/
  traversal.py          # Walks the Speckle Collection tree
  mapper.py             # Maps Speckle objects → IFC entity classes
  properties.py         # Extracts & writes attributes, property sets, quantities
  geometry.py           # Mesh → IFC geometry conversion
  instances.py          # Block instance / definition handling
  curves.py             # Curve geometry (Polycurve, Line, Arc)
  writer.py             # IFC scaffold creation, storey management
  type_manager.py       # IfcTypeObject creation & assignment
  materials.py          # Material mapping
  helpers.py            # Shared utilities (_get, unit scales)
  receiver.py           # Speckle server connection & data retrieval

Getting Started

Prerequisites

• Python 3.11+
• A Speckle account and project

Setup

python -m venv .venv
# Windows
.venv\Scripts\activate
# macOS/Linux
source .venv/bin/activate

pip install --upgrade pip
pip install .[dev]

Running Locally

Register and run via Speckle Automate, or test locally with Docker:

docker build -f ./Dockerfile -t ifc-exporter-rhino .
docker run --rm ifc-exporter-rhino python -u main.py run '<automation_context_json>' '<function_inputs_json>' <speckle_token>

Testing

pytest

Using with Speckle Automate

1. Go to the Automations tab in your project
2. Click New Automation
3. Select your function from the library
4. Configure function inputs and parameters
5. Choose a Speckle model to trigger the automation
6. Name your automation and click Create

Resources

• SpecklePy SDK
• Speckle Automate
• IFC 4.3 Documentation