# Model node links

<span class="badge text-bg-primary">Beginner</span>
<span class="badge text-bg-success">Artist</span>

>[!Note]
>In some versions of Stride, **Model node links** are called **Bone links**.

The **model node link** component attaches an entity to a node of a skeleton on another entity.

For example, imagine you have two models: a knight, and a sword. The character has a sword swinging animation. You can use a model link node to place the sword in the knight's hand and attach it to the correct node in the knight skeleton, so the sword swings with the knight animation.

<div class="ratio ratio-16x9 mb-3">
<video autoplay loop class="responsive-video" poster="../particles/tutorials/media/sword-slash-1.jpg">
   <source src="../particles/tutorials/media/sword-slash-1.mp4" type="video/mp4">
</video>
</div>

## Set up a model node link component

1. In the **Scene Editor**, select the entity you want to link to a node in another entity.
2. In the **Property Grid**, click **Add component** and select **Model node link**.

    ![Add component](../particles/tutorials/media/add-model-node-link.png)

    Game Studio adds a model node link component to the entity.

    ![Model node link component](media/model-node-component.png)

    The component only has two properties: **Node name** and **Target**.

3. Next to **Target**, click ![Hand icon](~/manual/game-studio/media/hand-icon.png).

    The **Select an entity** window opens.

    ![Select an entity](media/select-an-entity-window.png)

4. Select the model you want to link the entity to and click **OK**.

    > [!Note]
    > The entity you link to must have a model with a skeleton, even if the model isn't visible at runtime.

    > [!Tip]
    > If you don't specify a model, Stride links the entity to the model on the parent entity.

5. In **Node name**, select the node in the model you want to attach this entity to.

    ![Select node](media/select-node.png)

    After you link the node, the Entity Tree shows the link in blue next to the entity name.
    
    ![Model node link](media/model-node-link-sword-added.png)

## Offset

To add an offset to the linked entity, use the entity's [TransformComponent](xref:Stride.Engine.TransformComponent).

![Transform](media/transform-component.png)

> [!Note]
> If you don't want to add an offset, make sure the values are all set to `0,0,0`.

## Example script

This script demonstrates how to link one entity (such as a `SwordModel`) to a specific bone (`weapon_bone_R`) in another entity's skeleton hierarchy (in this case, the `mannequinModel`) using Stride's `ModelNodeLinkComponent`.

```csharp
public class BoneLink : StartupScript
{
    // This example assumes you've created a project with the default Stride models
    // "mannequinModel" and "SwordModel." Add them from the "Assets/Models" folder to your scene,
    // and then attach this script to the "SwordModel" entity

    ModelNodeLinkComponent boneLink;

    public override void Start()
    {
        // Initialize the script
        // Here we locate the entity named "mannequinModel" by searching the root scene's entities
        Entity owner = SceneSystem.SceneInstance.RootScene.Entities.Where(e => e.Name == "mannequinModel").Single();

        boneLink = new ModelNodeLinkComponent
        {
             // This is the ModelComponent on the target entity (mannequinModel)
            Target = owner.Get<ModelComponent>(),

            // We set a "hard link" to Nodes[70], which corresponds to "weapon_bone_R"
            // in the target's skeleton hierarchy
            NodeName = owner.Get<ModelComponent>().Model.Skeleton.Nodes[70].Name
        };

        // Finally, add this link component to our current (SwordModel) entity
        base.Entity.Components.Add(boneLink);
    }
}
```

## See also

* [Import animations](import-animations.md)
* [Animation properties](animation-properties.md)
* [Set up animations](set-up-animations.md)
* [Preview animations](preview-animations.md)
* [Animation scripts](animation-scripts.md)
* [Additive animation](additive-animation.md)
* [Procedural animation](procedural-animation.md)
* [Custom blend trees](custom-blend-trees.md)
* [Custom attributes](custom-attributes.md)

For examples of how model node links are used, see:

* [Particles — Create a trail](../particles/tutorials/create-a-trail.md)
* [Cameras — Animate a camera with a model file](../graphics/cameras/animate-a-camera-with-a-model-file.md)