> ## Documentation Index
> Fetch the complete documentation index at: https://docs.speckle.systems/llms.txt
> Use this file to discover all available pages before exploring further.

# ETABS Schema

> Data schema and structure for ETABS models

The ETABS connector exports structural analysis elements from CSI ETABS, preserving level organization and analysis results.

## Hierarchy

ETABS models are organized by File, Level, and Design Orientation:

```mermaid theme={null}
graph TD
    A[Root Collection] --> B[Etabs File]
    A --> C[Proxies: Section array]
    A --> D[Proxies: Material array]
    A --> E[Info: analysisResults<br/>optional]
    
    B --> F[Level]
    F --> G[Design Orientation]
    G --> H[EtabsObject]
```

The hierarchy reflects ETABS's organizational structure:

* **File** - The ETABS file
* **Level** - Building level/floor
* **Design Orientation** - Design orientation (X, Y, etc.)

## EtabsObject Structure

EtabsObject extends [DataObject](/developers/data-schema/object-schema) with these additional fields:

```json theme={null}
{
  "id": "string",
  "speckle_type": "Objects.Data.DataObject:Objects.Data.EtabsObject",
  "applicationId": "string",
  "name": "string",
  "properties": {
    "string": "any value"
  },
  "displayValue": [
    "Base (geometry objects)"
  ],
  "units": "string",
  
  "__comment": "EtabsObject-specific fields",
  "type": "string"
}
```

### Connector-Specific Fields

* **`type`** - The element type name (e.g., "Frame", "Area", "Point")

## Properties

EtabsObject `properties` contain:

* **Assignments** - Material, section, and property modifier assignments
* **Geometry properties** - Element geometry data
* **Object ID properties** - Label, level, and other identifier properties

```json theme={null}
{
  "properties": {
    "Assignments": {
      "Material": "Concrete",
      "Section": "W24x55",
      "Property Modifiers": {
        "Area": 1.0,
        "Moment of Inertia": 1.0
      }
    },
    "Geometry Properties": {
      "Length": 5.0,
      "Start Point": {"x": 0, "y": 0, "z": 0},
      "End Point": {"x": 5, "y": 0, "z": 0}
    },
    "Object ID Properties": {
      "Label": "Frame1",
      "Level": "Level 1",
      "Design Orientation": "X"
    }
  }
}
```

## Proxies

ETABS models use specialized proxy types:

### Section

Section proxies encode structural section definitions (e.g., W24x55, C10x20). Referenced by objects via `applicationId`.

### Material

Material proxies encode material definitions. Material proxy object IDs point to section proxies, creating a material → section relationship.

### RenderMaterial

Standard material assignments for visual representation.

## Info Fields

### analysisResults

Analysis results stored at the model level, including:

* **Base and joint reactions** - Reaction forces at supports
* **Frame and story forces** - Forces in frame elements and story levels
* **Story drifts** - Lateral displacement data

```json theme={null}
{
  "analysisResults": {
    "Base Reactions": [
      {
        "Joint": "J1",
        "Fx": 1000.0,
        "Fy": 500.0,
        "Fz": 2000.0,
        "Mx": 0.0,
        "My": 0.0,
        "Mz": 0.0
      }
    ],
    "Frame Forces": [
      {
        "Frame": "Frame1",
        "Station": 0.0,
        "P": 1000.0,
        "V2": 500.0,
        "V3": 200.0,
        "T": 0.0,
        "M2": 100.0,
        "M3": 50.0
      }
    ],
    "Story Drifts": [
      {
        "Story": "Story1",
        "DriftX": 0.01,
        "DriftY": 0.005
      }
    ]
  }
}
```

## Example: EtabsObject

```json theme={null}
{
  "id": "etabs-abc123...",
  "speckle_type": "Objects.Data.DataObject:Objects.Data.EtabsObject",
  "applicationId": "element-456",
  "name": "Frame - Frame1",
  "properties": {
    "Assignments": {
      "Material": "Steel",
      "Section": "W24x55",
      "Property Modifiers": {
        "Area": 1.0,
        "Moment of Inertia": 1.0
      }
    },
    "Geometry Properties": {
      "Length": 5.0,
      "Start Point": {"x": 0, "y": 0, "z": 0},
      "End Point": {"x": 5, "y": 0, "z": 0}
    },
    "Object ID Properties": {
      "Label": "Frame1",
      "Level": "Level 1",
      "Design Orientation": "X"
    }
  },
  "displayValue": [
    {
      "speckle_type": "Objects.Geometry.Line",
      "start": {"x": 0, "y": 0, "z": 0},
      "end": {"x": 5, "y": 0, "z": 0},
      "units": "meters"
    }
  ],
  "type": "Frame",
  "units": "meters"
}
```

## Invariants and Caveats

1. **No nested DataObjects** - EtabsObjects cannot contain other EtabsObjects as direct children
2. **Geometry in displayValue** - All visual geometry is in `displayValue`
3. **Specialized proxies** - ETABS uses Section and Material proxies, not just RenderMaterial
4. **Material → Section relationship** - Material proxies reference section proxies
5. **Analysis results in Info** - Model-level analysis data is in `info.analysisResults`
6. **Design orientation** - Objects are organized by design orientation in addition to level

<Accordion title="What's the difference between Section and Material proxies?">
  * **Section**: Defines the structural cross-section (e.g., W24x55 wide flange, C10x20 channel)
  * **Material**: Defines the material properties (e.g., Steel A36, Concrete 3000psi). Material proxies reference section proxies to create material-section combinations.
</Accordion>

<Accordion title="How do I access analysis results?">
  Analysis results are stored in the Root Collection's `info.analysisResults` field. This is model-level data, not per-object. Access it from the root collection object, not from individual EtabsObjects.
</Accordion>

## Related Documentation

* [Object Schema](/developers/data-schema/object-schema) - Base object structure
* [Proxy Schema](/developers/data-schema/proxy-schema) - How proxies work