# Engine

The `engine` bone corresponds to the **Engine** component. It can be either invisible or contain a visible mesh.\
It has a volume, `engine_vol`, which is hidden inside the volumes of the `body_vol` group.

**Properties of the `engine` bone**

<table data-header-hidden><thead><tr><th width="167">Property</th><th>Description</th></tr></thead><tbody><tr><td><code>poly</code></td><td>Makes the component visible.</td></tr><tr><td><code>id=engine</code></td><td>Identifier of the <strong>Engine</strong> component.</td></tr><tr><td><code>Animation</code></td><td>Specifies the animation name (if available).</td></tr></tbody></table>

#### **Checklist of possible elements linked to the `engine` bone**

<figure><img src="/files/UwOKEo0QvdC9pCENfuHb" alt=""><figcaption><p>Elements linked to the engine bone</p></figcaption></figure>

Depending on the model, the following elements may be linked to the `engine` bone

* Engine\_LOD branches
* **Secondary bones**
  * `cover`:  hatch bones, if specified by the model's design
  * `detail`: additional details, if specified by the model's design
* **Helper bones**:
  * &#x20;`FXsmoke`: exhaust smoke effec
  * &#x20;`FXfire`: engine fire effect
  * &#x20;`fxstop1`: brake lights
  * &#x20;`seat`: bones for passengers


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://bestway-1.gitbook.io/documentation/modeling/vehicle-model-setup-pipeline/bone-hierarchy-in-vehicle-models/engine.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.