FrontFacing(3)

# FrontFacing(3) Manual Page

## Name

FrontFacing - Front face determination of a fragment

## Description

`FrontFacing`

  Decorating a variable with the `FrontFacing` built-in decoration will make that variable contain whether the fragment is front or back facing. This variable is non-zero if the current fragment is considered to be part of a front-facing polygon primitive or of a non-polygon primitive and is zero if the fragment is considered to be part of a back-facing polygon primitive.

Valid Usage

- VUID-FrontFacing-FrontFacing-04229
  The `FrontFacing` decoration must be used only within the `Fragment` `Execution` `Model`

- VUID-FrontFacing-FrontFacing-04230
  The variable decorated with `FrontFacing` must be declared using the `Input` `Storage` `Class`

- VUID-FrontFacing-FrontFacing-04231
  The variable decorated with `FrontFacing` must be declared as a boolean value

## See Also

No cross-references are available

## Document Notes

For more information, see the Vulkan Specification.

This page is extracted from the Vulkan Specification. Fixes and changes should be made to the Specification, not directly.

## Copyright

Copyright 2014-2026 The Khronos Group Inc.

SPDX-License-Identifier: CC-BY-4.0