---
title: USDLayer.Spec.FieldCollection
framework: usdkit
role: symbol
role_heading: Protocol
path: usdkit/usdlayer/spec/fieldcollection
---

# USDLayer.Spec.FieldCollection

Low-level read/write access to spec fields. Fields are the raw data backing both metadata and structural information on a spec.

## Declaration

```swift
protocol FieldCollection
```

## Topics

### Instance Properties

- [fields](usdkit/usdlayer/spec/fieldcollection/fields.md)

### Instance Methods

- [clearField(_:)](usdkit/usdlayer/spec/fieldcollection/clearfield(_:).md)
- [field(_:)](usdkit/usdlayer/spec/fieldcollection/field(_:).md)
- [field(_:as:)](usdkit/usdlayer/spec/fieldcollection/field(_:as:).md)
- [isInert(ignoringChildren:)](usdkit/usdlayer/spec/fieldcollection/isinert(ignoringchildren:).md)
- [setField(_:to:)](usdkit/usdlayer/spec/fieldcollection/setfield(_:to:)-26nys.md)
- [setField(_:to:)](usdkit/usdlayer/spec/fieldcollection/setfield(_:to:)-4lcqw.md)

## Relationships

### Conforming Types

- [USDLayer.Spec](usdkit/usdlayer/spec.md)
- [USDPrim.Attribute.Spec](usdkit/usdprim/attribute/spec.md)
- [USDPrim.Property.Spec](usdkit/usdprim/property/spec.md)
- [USDPrim.PseudoRootSpec](usdkit/usdprim/pseudorootspec.md)
- [USDPrim.Relationship.Spec](usdkit/usdprim/relationship/spec.md)
- [USDPrim.Spec](usdkit/usdprim/spec.md)
- [USDPrim.VariantSetSpec](usdkit/usdprim/variantsetspec.md)
- [USDPrim.VariantSpec](usdkit/usdprim/variantspec.md)