Skin Tools and Maya integration and compatibility

This section covers how Skin Tools interacts with, and in some cases overrides, native Maya functionality.

Cleanup and deletion behavior

The Skin Tools custom node is automatically removed when the associated skinCluster is deleted or unbound.

This cleanup occurs with the following standard Maya operations:

• Skin > Unbind Skin (Delete option)
• Skin > Unbind Skin (Bake option)
• Deleting the skinCluster node directly in the Outliner or Node Editor
• Edit > Delete by Type > History (when it removes the skinCluster)

No manual cleanup of Skin Tools data is required.

Preferred Paint Skin Weights tool

You can choose which tool is launched when selecting Skin > Paint Skin Weights

In Preferences > Animation > Rigging, the Paint Skin Weights Tool preference provides the following options:

• Classic Paint Skin Weights Tool (default)
• Skin Tools Paint Skin Weights Tool

This preference determines which tool opens when invoking the Paint Skin Weights command from the Skin menu.

Maya tool compatibility

Several native Maya skinning tools are incompatible with the Skin Tools layer system because they operate directly on the base skin cluster, which would bypass or corrupt the layer data. When layers are present, these tools are blocked and will display an error message directing the user to the appropriate Skin Tools workflow.

Incompatible Maya tool	Recommended Skin Tools alternative
Classic Paint Skin Weights Tool	Use the Skin Tools Paint interface.
Set Max Influences	Use the influence limit settings in the Paint/Set Weights or Effects tab.
Hammer Skin Weights	Use the smoothing tools available in the Skin Tools Paint tab.
Paste Skin Weights	Use the Copy and Paste functions in Skin Tools.
Move Weights to Influences	Bake or delete Skin Tools layers before using Move Weights to Influences.
Import Weight Maps	Bake or delete Skin Tools layers before importing weight maps.
Mirror Skin Weights	Use the mirror functionality in Skin Tools (Interactive Mirror in the Paint tab or Mirror tab operations).
Substitute Geometry	Bake or delete Skin Tools layers before using Substitute Geometry. To transfer layered skin data between geometries, use the Skin Tools Export and Import functions.
Normalize Skin Weights	Not necessary; Skin Tools handles normalization automatically.

Enhanced Maya Commands

Smooth Skin Weights

Menu location: Skin > Smooth Skin Weights

The Smooth Skin Weights command uses the Skin Tools smoothing algorithm by default. You can switch to the Legacy method in the Method options.

When using the Skin Tools method:

• If the skinCluster has no skinning layers, a temporary layer is created to perform smoothing and removed afterward.
• If the skinCluster has a single skinning layer, that layer is smoothed.
• If the skinCluster has multiple skinning layers, an error is displayed directing you to use the smoothing tools available in the Skin Tools interface.

To smooth weights when working with multiple skinning layers, use:

• The Smooth brush in the Paint tab.
• The Smooth mode in the Set Weights section.

Skin Tools smoothing operates per layer and is compatible with layered workflows.

Behavior with Skin Tools Method:

• No Layers: A temporary layer is created for the operation and then removed.
• Single Layer: Smoothing is applied directly to the single existing layer.

• Multiple Layers: An error is generated, directing the user to the Skin Tools UI to select a specific layer to smooth.

Reset Default Skin Weights

When skinning layers are present on a skinCluster, using Skin > Reset Default Skin Weights prompts you to bake the skin layers before resetting.

If confirmed, the following sequence occurs:

1. Skin layers are baked.
2. Default skin weights are restored.
3. Skin layers are re-initialized.

This ensures that layered data is preserved appropriately during the reset process.