# 3d-tiles-renderer/core/plugins

```js
import { ... } from '3d-tiles-renderer/core/plugins';
```

### Classes

- [CesiumIonAuth](/tools/docs/3d-tiles-renderer/core/plugins/CesiumIonAuth.md): Authentication helper for Cesium Ion. Fetches and caches a bearer token from the Cesium Ion endpoint and injects it into outgoing requests. Supports optional automatic token refresh on 4xx responses.
- [CesiumIonAuthPlugin](/tools/docs/3d-tiles-renderer/core/plugins/CesiumIonAuthPlugin.md): Plugin for authenticating requests to Cesium Ion. Handles token refresh, asset endpoint resolution, and attribution collection. Automatically registers a GoogleCloudAuthPlugin when the resolved asset is an external Google photorealistic tileset.
- [EnforceNonZeroErrorPlugin](/tools/docs/3d-tiles-renderer/core/plugins/EnforceNonZeroErrorPlugin.md): Plugin that ensures every tile has a non-zero geometric error. Tiles with a geometric error of zero are assigned a derived value based on the nearest ancestor with a non-zero error, halved once per level of depth below that ancestor.
- [GoogleCloudAuth](/tools/docs/3d-tiles-renderer/core/plugins/GoogleCloudAuth.md): Authentication helper for Google Cloud Maps APIs. Manages session-token creation and renewal for both the Photorealistic 3D Tiles API and the 2D Map Tiles API, injecting the API key and session token into outgoing requests.
- [GoogleCloudAuthPlugin](/tools/docs/3d-tiles-renderer/core/plugins/GoogleCloudAuthPlugin.md): Plugin for authenticating requests to the Google Cloud Maps APIs, including the Photorealistic 3D Tiles and 2D Map Tiles APIs. Handles session-token management, per-tile attribution collection, and optional logo attribution.
- [ImplicitTilingPlugin](/tools/docs/3d-tiles-renderer/core/plugins/ImplicitTilingPlugin.md): Plugin that adds support for 3D Tiles 1.1 implicit tiling. Intercepts tiles that carry an `implicitTiling` field and expands them by loading and parsing `.subtree` files, generating child tiles according to the implicit subdivision scheme.
- [QuantizedMeshLoaderBase](/tools/docs/3d-tiles-renderer/core/plugins/QuantizedMeshLoaderBase.md): Base loader for quantized-mesh terrain tiles. Parses the binary quantized-mesh format into structured vertex, index, edge, and extension data. Sets the required `Accept` header automatically. Subclasses should implement geometry construction from the parsed result.

### Types

- [ParsedBitstream](/tools/docs/3d-tiles-renderer/core/plugins/ParsedBitstream.md)