---
title: SCNBindingBlock
framework: scenekit
role: symbol
role_heading: Type Alias
path: scenekit/scnbindingblock
---

# SCNBindingBlock

The signature for a block called for binding or unbinding a GLSL symbol in a custom program.

## Declaration

```swift
typealias SCNBindingBlock = (UInt32, UInt32, SCNNode?, SCNRenderer) -> Void
```

## Discussion

Discussion The block takes the following parameters: Call handleBinding(ofSymbol:handler:) or handleUnbinding(ofSymbol:handler:) to associate a handler block with a GLSL symbol for a SceneKit geometry or material.

## See Also

### Constants

- [SCNShaderModifierEntryPoint](scenekit/scnshadermodifierentrypoint.md)