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				Related nodes. Attributes. 
 Surface Luminance is a utility node that tells you
 the luminance (brightness) of a point on a surface as it is
 being rendered.  This luminance takes into account all the light
 sources shining on the object, and the angle at which they shine
 on the object.  It does not take into account the specular properties
 of the object itself, such as 'hotspots'.
 
 You can use this node to make interesting shaders that change
 based on the light in the environment.
 
 Example:  Say you are modelling a windscreen of a car, made of
 a special glass that
 becomes darker (more opaque) in bright light.  To do this,
 create a Surface Luminance node, and connect its output to all three
 input channels of a Reverse node.  Then connect the output of the
 Reverse node to the Transparency attribute of a shader.
 
 In the table below, important attributes have their names
 listed in bold in the description column.
This node is MP safe
| Node name | Parents | Classification | MFn type | Compatible function sets | 
|---|
| surfaceLuminance | node | utility/color:drawdb/shader/operation/surfaceLuminance | kSurfaceLuminance | kBase kNamedObject
 kDependencyNode
 kSurfaceLuminance
 | 
Related nodes
blendColors, clamp, lightInfo, gammaCorrect, contrast, luminance, rgbToHsv, hsvToRgb, samplerInfo, setRange, resolution, renderQuality, renderGlobals, renderGlobalsList, baseShadingSwitch, singleShadingSwitch, doubleShadingSwitch, tripleShadingSwitch
Attributes (20)
lightAmbient, lightBlindData, lightDataArray, lightDiffuse, lightDirection, lightDirectionX, lightDirectionY, lightDirectionZ, lightIntensity, lightIntensityB, lightIntensityG, lightIntensityR, lightShadowFraction, lightSpecular, normalCamera, normalCameraX, normalCameraY, normalCameraZ, outValue, preShadowIntensity
| Long name (short name) | Type | Default | Flags | 
|---|
|  | 
| normalCamera(n) | float3 | 0.0, 0.0, 1.0 |     | 
|
| |  |  | normalCameraX(nx) | float | 0.0 |     |  |
 | 
| |  |  | normalCameraY(ny) | float | 0.0 |     |  |
 | 
| |  |  | normalCameraZ(nz) | float | 0.0 |     |  |
 | 
|  | 
| lightDataArray(ltd) | lightData | NULL |     | 
|
| |  |  | lightDirection(ld) | float3 |  |    |  |
 | |  |  | lightDirectionX(ldx) | float | 1.0 |    |  |
 |  | |  |  | lightDirectionY(ldy) | float | 1.0 |    |  |
 |  | |  |  | lightDirectionZ(ldz) | float | 1.0 |    |  |
 | 
 | 
| |  |  | lightIntensity(li) | float3 |  |    |  |
 | |  |  | lightIntensityR(lir) | float | 1.0 |    |  |
 |  | |  |  | lightIntensityG(lig) | float | 1.0 |    |  |
 |  | |  |  | lightIntensityB(lib) | float | 1.0 |    |  |
 | 
 | 
| |  |  | lightAmbient(la) | bool | true |    |  |
 | 
| |  |  | lightDiffuse(ldf) | bool | true |    |  |
 | 
| |  |  | lightSpecular(ls) | bool | false |    |  |
 | 
| |  |  | lightShadowFraction(lsf) | float | 0.0 |    |  |
 | 
| |  |  | preShadowIntensity(psi) | float | 0.0 |    |  |
 | 
| |  |  | lightBlindData(lbd) | addr | NULL |    |  |
 | 
|  | 
| outValue(o) | float | 0.0 |   | 
|