2011 Khronos Group
faceforward 3G
faceforward return a vector pointing in the same direction as another

## Declaration

genType `faceforward` genType N genType I genType Nref genDType `faceforward` genDType N genDType I genDType Nref

## Parameters

N

  Specifies the vector to orient.

I

  Specifies the incident vector.

Nref

  Specifies the reference vector.

## Description

`faceforward` orients a vector to point away from a surface as defined by its normal. If dot`(Nref, I) < 0` `faceforward` returns N, otherwise it returns `-N`.

## Version Support

#VARTABLECOLS#
#FUNCTABLEHEADER#
faceforward (genType)#newin11#
faceforward (genDType)#newin40#

## See Also

reflect, refract

## Copyright

Copyright 2011 Khronos Group. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. http://opencontent.org/openpub/.