---
title: CustomPartLoader
framework: hvf
role: symbol
role_heading: Type Alias
platforms: [iOS 18.4+, iPadOS 18.4+, Mac Catalyst 18.4+, macOS 15.4+, tvOS 18.4+, visionOS 2.4+, watchOS 11.4+]
path: hvf/custompartloader
---

# CustomPartLoader

Closure which loads parts from an arbitrary source The first parameter is the part index which uniquely identifiers a part; these are assigned by the loader The second parameter is a PartGenerator the loader uses to get a ShapeWriter or CompositeWriter to create the requested part The result is the generated part, passed back in a PartResult

## Declaration

```swift
typealias CustomPartLoader = (Int, any PartGenerator) -> PartResult
```