---
title: "init(front:back:extrusion:frontChamfer:backChamfer:)"
framework: realitykit
role: symbol
role_heading: Initializer
path: "realitykit/meshresource/shapeextrusionoptions/materialassignment-swift.struct/init(front:back:extrusion:frontchamfer:backchamfer:)"
---

# init(front:back:extrusion:frontChamfer:backChamfer:)

Creates a material assignment structure with options for each side of an extruded shape.

## Declaration

```swift
init(front: UInt32 = 0, back: UInt32 = 0, extrusion: UInt32 = 0, frontChamfer: UInt32 = 0, backChamfer: UInt32 = 0)
```

## Parameters

- `front`: The material index for the front face of the shape.
- `back`: The material index for the back face of the shape.
- `extrusion`: The material index for the extruded faces of the shape.
- `frontChamfer`: The material index for the chamfered edges between the front and sides of the shape.
- `backChamfer`: The material index for the chamfered edges between the back and sides of the shape.

## Discussion

Discussion The default for any omitted parameter is 0.