LightDirection
Keywords: LightDirection, NVIDIA, NVIDIA Cg Toolkit, Cg Toolkit, Shader, Shader Programming, GPU Shader Programming, GPU Program

> ## Name

> LightDirection - 3D API light direction

> ## Usage

> LightDirection[i] = float4(x, y, z, w)

> ## Valid Enumerants

> x, y, z, w: floating point values

> ## Description

> Specify the lights direction. See the GL_SPOT_DIRECTION description on the OpenGL glLight manual page for details. See the Direction member of the D3DLIGHT9 argument to IDirect3DDevice9::SetLight method.

> The standard reset callback sets the LightDirection[i] state to float4(0, 0, -1, 1).

> ## Opengl Functionality Requirements

> OpenGL 1.0

> ## Direct3D Functionality Requirements

> DirectX 9

> ## See Also

> LightAmbient, LightAttenuation0, LightAttenuation1, LightAttenuation2, LightConstantAttenuation, LightDiffuse, LightEnable, LightFalloff, LightLinearAttenuation, LightModelAmbient, LightModelColorControl, LightModelLocalViewerEnable, LightModelTwoSideEnable, LightPhi, LightPosition, LightQuadraticAttenuation, LightRange, LightSpecular, LightSpotCutoff, LightSpotDirection, LightSpotExponent, LightTheta, LightType, LightingEnable