exposure: Alternative scale on the contribution of this light. Increasing by 1 doubles the intensity, decreasing by 1 halves it. Leave at 0 to use the intensity parameter as-is.
sunTint: Tweak the sun’s contribution and color. The default, white (1,1,1), gives results based on measured physical values.
sunSize: Scale the apparent size of the sun in the sky. Leave at 1 for a realistic sun size with an 0.55 degree angular diameter.
method: The sun direction can either be specified as a vector or using the heliodon.
directionVector: The apparent direction towards the center of the sun. The zenith is at +Y (for noon light) and the horizon is in the XZ plane (for sunrise/set). Note that the Y component must non-negative.
month: Month of the year, 1 through 12.
day: Day of the month, 1 through 31.
year: Four-digit year.
hour: Hours since midnight, local standard time. May be fractional to include minutes and seconds. If daylight saving time is in effect, subtract 1 to correct to standard time.
zone: Standard time zone offset from GMT/UTC in hours. Positive for east, negative for west. For example, this would be -8 for Pacific time.
latitude: Latitude in degrees. Positive for north, negative for south.
longitude: Longitude in degrees. Positive for east, negative for west.
haziness: The turbidity of the sky. The lower limit of the model is 1.7 for an exceptionally clear sky, and 10, for an inversion, is the upper limit.
skyTint: Tweak the sky’s contribution and color. The default, white (1,1,1), gives results based on measured physical values.
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.
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: Scales the contribution of this light. With an intensity of 1e+5, the model computes physically plausible results in cd/m^2 units. This makes it about 100k too bright for typically displayed RGB values, so we internaly scale by default by 1e-5.
__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.