---
title: IsNull()
product: Unity Editor
version: '7000.0'
latest_version: '7000.0'
status: This page documents version 7000.0. The latest version is 7000.0.
canonical: https://docs.unity.com/en-us/engine/7000.0/script-reference/unityengine/experimental/ai/polygonid/isnull
latest_url: https://docs.unity.com/en-us/engine/7000.0/script-reference/unityengine/experimental/ai/polygonid/isnull.md
last_updated: 2026-10-07
generated_at: 2026-11-11T23:28:34.566Z
locale: en-us
---

# IsNull()

> Returns true if the PolygonId has been created empty and has never pointed to any node in the NavMesh.

## Definition

* **Type:** Method
* **Namespace:** [UnityEngine.Experimental.AI](/engine/7000.0/script-reference/unityengine/experimental/ai.md)
* **Assembly:** UnityEngine.AIModule

> **Warning:**
>
> **Deprecated.** The experimental PolygonId struct has been deprecated. Use NavNode instead.

```csharp
public bool IsNull()
```

### Returns

| Type                                                          | Description |
| ------------------------------------------------------------- | ----------- |
| [bool](https://learn.microsoft.com/dotnet/api/system.boolean) |             |