Parameters
rman__Shape: Specifies the shape of the area light emitter.
exposure: Specifies the intensity of the area light as a power of 2. Increasing the intensity by 1 will double the energy emitted by the light source. A value of 0 produces an intensity of 1, -1 produces .5.
lightColor: The color of the emitted light.
enableTemperature: Enable plausible color temperature.
temperature: Allow the user to choose the color temperature of the light. Unlike the basic light color this allows the user to easily pick plausible light colors based on standard temperature measurements in Kelvins. Defaults to 6500 K, the D65 illuminant used by sRGB and Rec. 709.
rman__EmissionMap: An optional color map for emitted light.
linearizeEmissionMap: Linearize the color map. This is only necessary for 8 or 16 bits textures. HDR (exr) textures are generally already in linear color space.
rman__ProceduralResolution: This resolution only affects textured rect lights. To adjust the resolution of other textured lights, set the ShadingRate parameter on the light. The Automatic option will result in using the size of the image specified in the Color Map parameter. Currently the rect light resolution must be a square power of 2.
emissionMapScaleS: Scales the emission map S texture coordinates by this amount.
emissionMapScaleT: Scales the emission map T texture coordinates by this amount.
emissionMapOffsetS: Offsets the emission map S texture coordinates by this amount.
emissionMapOffsetT: Offsets the emission map T texture coordinates by this amount.
specAmount: Scale the specular contribution of this light.
diffAmount: Scale the diffuse contribution of this light.
fixedSampleCount: Overide the automatic sample allocation and use a fixed number instead. Values smaller than 1 disable this feature.
importance: Overide the automatic sample allocation. An importance of 2 will allocate twice the regular sample budget to this light.
coneAngle: Spot cone angle
penumbraAngle: Spot cone angle
penumbraExponent: Change the falloff of the penumbra.
profileMap: Name of the emission color map.
iesProfile: Name of the IES emission map.
profileRange: Rescales the angular distribution of the ies profiles. Values less than 180 specify that the profile represents less angular coverage, and will effectively increase the size of the projected profile.
profileSpace: Name of the space that the light profile is in.
distributionAngle: Focusing power of the geometric area lights. Range is 0 to 90
angularVisibility: Specifies the size of the highlight as a angle. Only valid when 'Shape' is set to distant.
barnDoorMap: Barn doors are implemented as gobos, so they need a texture map. Idealy this would just be a black texture.
enableShadows: Enable raytraced shadows.
shadowColor: The color of the shadows cast by emitted light.
shadowMaxDist: Limits the shadow distance. Any value smaller or equal to 0.0 will be ignored and the shadow distance will be unlimited. Defaults to -1 : unlimited shadow distance.
shadowTraceBias: Raytracing bias for shadow computations. -1 uses automatically computed value value.
shadowSubset: Set of geometry to consider for traced shadow intersection.
shadowExcludeSubset: Set of geometry to ignore for traced shadow intersection.
intensity: Legacy. Keep at 1.
areaNormalize: When normalize is enabled, the amount of light contributed to the scene will not change as you scale the light source. This makes it easier to adjust highlight size without changing scene lighting drastically.
__group: The group is a special type of attribute which allows you to provide light category support for geometric area lights, as well as per group AOVs for the lighting on the surface.