# ModelImporterIndexFormat

> Format of the imported mesh index buffer data.

## Definition

* **Type:** Enum
* **Namespace:** [UnityEditor](/engine/6000.0/script-reference/unityeditor.md)
* **Assembly:** UnityEditor

```csharp
public enum ModelImporterIndexFormat
```

## Remarks

Index buffer can either be 16 bit (supports up to 65535 vertices in a mesh), or 32 bit (supports up to 4 billion vertices). Default behavior is [ModelImporterIndexFormat.Auto](/engine/6000.0/script-reference/unityeditor/modelimporterindexformat/auto.md), which picks the format based on vertex count in the mesh.

Additional Resources: [ModelImporter.indexFormat](/engine/6000.0/script-reference/unityeditor/modelimporter/indexformat.md), [Mesh.indexFormat](/engine/6000.0/script-reference/unityengine/mesh/indexformat.md).

## Fields

| Value                                                                                    | Description                                           |
| ---------------------------------------------------------------------------------------- | ----------------------------------------------------- |
| [Auto](/engine/6000.0/script-reference/unityeditor/modelimporterindexformat/auto.md)     | Use 16 or 32 bit index buffer depending on mesh size. |
| [UInt16](/engine/6000.0/script-reference/unityeditor/modelimporterindexformat/uint16.md) | Use 16 bit index buffer.                              |
| [UInt32](/engine/6000.0/script-reference/unityeditor/modelimporterindexformat/uint32.md) | Use 32 bit index buffer.                              |