<!--
{
  "availability" : [
    "iOS: 27.0.0 -",
    "iPadOS: 27.0.0 -",
    "tvOS: 27.0.0 -",
    "visionOS: 27.0.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "RealityKit",
  "identifier" : "/documentation/RealityKit/LowLevelMaterialParameterMapping",
  "metadataVersion" : "0.1.0",
  "role" : "Structure",
  "symbol" : {
    "kind" : "Structure",
    "modules" : [
      "RealityKit"
    ],
    "preciseIdentifier" : "s:19RealityCoreRenderer32LowLevelMaterialParameterMappingV"
  },
  "title" : "LowLevelMaterialParameterMapping"
}
-->

# LowLevelMaterialParameterMapping

A mapping of named buffer and texture parameters to binding indices for a compiled
shader function.

```
struct LowLevelMaterialParameterMapping
```

## Overview

Use `bufferLocation(named:)`, `constantLocation(named:)`, and `textureLocation(named:)`
to look up the binding index for a named parameter, then bind a resource to that slot
with [`setBufferSlice(_:at:)`](/documentation/RealityKit/LowLevelArgumentTable/setBufferSlice(_:at:)) or
[`setTexture(_:at:)`](/documentation/RealityKit/LowLevelArgumentTable/setTexture(_:at:)).

## Topics

### Accessing parameter mappings

[`var buffers: [LowLevelMaterialParameterMapping.Buffer]`](/documentation/RealityKit/LowLevelMaterialParameterMapping/buffers)

The ordered buffer slot descriptions for this function.

[`enum Buffer`](/documentation/RealityKit/LowLevelMaterialParameterMapping/Buffer)

The contents of a buffer slot, either a collection of packed constants or a single
structured buffer.

[`struct BufferParameter`](/documentation/RealityKit/LowLevelMaterialParameterMapping/BufferParameter)

A structured buffer parameter.

[`var textures: [LowLevelMaterialParameterMapping.TextureParameter]`](/documentation/RealityKit/LowLevelMaterialParameterMapping/textures)

The ordered texture slot descriptions for this function.

[`struct TextureParameter`](/documentation/RealityKit/LowLevelMaterialParameterMapping/TextureParameter)

A texture parameter.

[`struct ConstantParameter`](/documentation/RealityKit/LowLevelMaterialParameterMapping/ConstantParameter)

A constant parameter embedded within a buffer slot.

### Locating parameters

[`func bufferLocation(named: String) -> Int?`](/documentation/RealityKit/LowLevelMaterialParameterMapping/bufferLocation(named:))

Returns the argument table buffer slot index for the named buffer parameter, or `nil`
if no parameter with that name exists.

[`func textureLocation(named: String) -> Int?`](/documentation/RealityKit/LowLevelMaterialParameterMapping/textureLocation(named:))

Returns the argument table texture slot index for the named texture parameter, or `nil`
if no parameter with that name exists.

[`func constantLocation(named: String) -> LowLevelMaterialParameterMapping.ConstantLocation?`](/documentation/RealityKit/LowLevelMaterialParameterMapping/constantLocation(named:))

Returns the resolved buffer and constant indices for the named constant parameter, or
`nil` if no parameter with that name exists.

[`struct ConstantLocation`](/documentation/RealityKit/LowLevelMaterialParameterMapping/ConstantLocation)

The resolved buffer and constant slot indices for a named constant parameter.

## Relationships

### Conforms To

[`SendableMetatype`](/documentation/Swift/SendableMetatype)

[`Sendable`](/documentation/Swift/Sendable)

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)