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The AutoCAD connector exports geometry and objects from AutoCAD, preserving layer organization and extended data.

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Hierarchy

AutoCAD models are organized by File and Layer: 
Root Collection
├── AutoCAD File
│   └── Layer
│       ├── Geometry (standalone)
│       └── Instance
├── Proxies: RenderMaterial[]
├── Proxies: Color[]
├── Proxies: Group[]
└── Proxies: Definition[]
The hierarchy reflects AutoCAD’s layer structure:
  • File - The AutoCAD file
  • Layer - AutoCAD layer

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Object Types

AutoCAD exports three types of objects:
  1. Geometry - Standalone geometry objects (Point, Line, Polyline, Arc, etc.)
  2. Instance - Block references pointing to Definition proxies
  3. DataObject - Objects with attached extended data (less common)

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Geometry Objects

Standalone geometry objects can appear directly in collections: 
{
  "speckle_type": "Objects.Geometry.Line",
  "id": "...",
  "applicationId": "handle-123",
  "start": {"x": 0, "y": 0, "z": 0},
  "end": {"x": 10, "y": 10, "z": 0},
  "units": "meters"
}

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Instance Objects

Instance objects reference Definition proxies for block definitions: 
{
  "speckle_type": "Objects.Instance",
  "applicationId": "instance-handle",
  "definitionId": "block-guid",
  "transform": {
    "speckle_type": "Objects.Geometry.Matrix",
    "value": [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 10, 20, 30, 1]
  },
  "units": "meters"
}

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Properties

Geometry and Instance objects can have a properties field dynamically attached containing:
  • Extension Dictionaries - Custom data stored in extension dictionaries
  • XData - Extended entity data
{
  "speckle_type": "Objects.Geometry.Line",
  "applicationId": "handle-123",
  "start": {"x": 0, "y": 0, "z": 0},
  "end": {"x": 10, "y": 10, "z": 0},
  "properties": {
    "Extension Dictionaries": {
      "CustomApp": {
        "Key1": "Value1",
        "Key2": "Value2"
      }
    },
    "XData": {
      "AppName": "MyApp",
      "Data": [1001, "Tag", 1002, "Value"]
    }
  },
  "units": "meters"
}

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Proxies

AutoCAD models use these proxy types:

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RenderMaterial

Material assignments for visual representation.

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Color

Color assignments for objects. Referenced by objects via applicationId.

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Group

Group proxies encode AutoCAD group memberships. Objects can belong to multiple groups.

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Definition

Definition proxies store geometry for block definitions. Referenced by Instance objects via definitionId.

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Example: AutoCAD Geometry Object

{
  "id": "line-abc123...",
  "speckle_type": "Objects.Geometry.Line",
  "applicationId": "handle-456",
  "start": {"x": 0, "y": 0, "z": 0},
  "end": {"x": 10, "y": 10, "z": 0},
  "properties": {
    "Extension Dictionaries": {
      "MyApp": {
        "Layer": "A-WALL",
        "Type": "Structural"
      }
    }
  },
  "units": "meters"
}

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Example: AutoCAD Instance

{
  "id": "instance-xyz789...",
  "speckle_type": "Objects.Instance",
  "applicationId": "instance-handle-789",
  "definitionId": "block-door",
  "transform": {
    "speckle_type": "Objects.Geometry.Matrix",
    "value": [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 5, 10, 0, 1]
  },
  "units": "meters"
}

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Invariants and Caveats

  1. Standalone geometry - Geometry objects can exist directly in collections
  2. Instance/Definition pattern - Block instances use the Instance/Definition proxy pattern
  3. Properties are optional - Not all geometry objects have properties
  4. Layer organization - Objects are organized by AutoCAD’s layer structure
  5. Extended data in properties - Extension dictionaries and XData appear in properties field
  6. No Info fields - AutoCAD models don’t include Info fields
Use the Instance’s definitionId to find the corresponding Definition proxy, then access proxy.value.displayValue to get the geometry. See Traversal Recipes for a complete example.