RenderManMeshLight
Turns mesh primitives into RenderMan mesh lights by assigning a PxrMeshLight shader, turning off all visibility except for camera rays, and adding the meshes to the default lights set.
user
Container for user-defined plugs. Nodes should never make their own plugs here, so users are free to do as they wish.
out
The processed output scene.
enabled
The on/off state of the node. When it is off, the node outputs the input scene unchanged.
in
The input scene
filter
The filter used to control which parts of the scene are processed. A Filter node should be connected here.
cameraVisibility
Whether or not the mesh light is visible to camera rays.
parameters
The parameters of the PxrMeshLight shader that is applied to the meshes.
parameters.intensity
intensity: Scales the contribution of this light linearly. The light intensity is computed using
physical units.
parameters.exposure
exposure: Specifies the exposure of the area light as a power of 2. Increasing the exposure by 1
will double the energy emitted by the light source. A value of 0 produces an intensity
of 1 at the source, -1 produces 0.5. Real world lighting has high energies and typical
exposures are low values while you may have to type a really large number for
equivalent Intensity. This is also comfortable to artists familiar with photographic
measurements.
parameters.lightColor
lightColor: The color of the emitted light.
parameters.textureColor
textureColor: An image to use as a light source. Preferably a High Dynamic Range source. Notice
this affects color and shadowing based on the contents of the HDRI used. If forced to
use an 8-bit source such as a JPEG image, it should be linearized (transformed to linear
color space) before use as a color. Since this is indeed a mesh, you must have defined
UVs or appropriate projections to place your texture correctly.
parameters.enableTemperature
enableTemperature: Turns color temperature on or off.
parameters.temperature
temperature: Allow the user to choose the color temperature of the light in Kelvins. Unlike the
basic light color, this allows the user to easily pick plausible light colors based on
standard temperature measurements.This control will act like a filter or gel (a tinted
transparent surface) in front of your light. If your light is white, you will get the
chosen color temperature. If your light is colored, the color temperature will make it
cooler (over 6500K) or warmer (below 6500K). The effect will be less pronounced on fully
saturated mono-chromatic lights. Defaults to 6500K, which should be very close to white
on most monitors (D65 illuminant used by sRGB and Rec 709).
parameters.specular
specular: Amount of specular light that is emitted. This is a non-physical control. You
could use a light with Specular Amount 0.0 to act purely as a source of diffuse light for
your scene objects and avoid adding highlights.
parameters.diffuse
diffuse: Amount of diffuse light that is emitted. This is a non-physical control. You
could use a light with Diffuse Amount 0.0 to act purely as a source of highlights for
your scene objects.
parameters.intensityNearDist
intensityNearDist: Near distance between the point being illuminated and the light
at which the sample doesn't get brighter. This may help you avoid hot spots and
sampling issues where a light is near a surface.
parameters.specularNearDist
specularNearDist: Near distance between the point with specular shading being illuminated
and the light at which the sample doesn't get brighter. This may help you
avoid hot spots and sampling issues where a light is near a specular surface.
Note that this value will not apply to lights as seen from the camera.
parameters.diffuseNearDist
diffuseNearDist: Near distance between the point with diffuse shading being illuminated
and the light at which the sample doesn't get brighter. This may help you
avoid hot spots and sampling issues where a light is near a diffuse surface.
Note that this value will not apply to lights as seen from the camera.
parameters.enableShadows
enableShadows: Enable raytraced shadows.
parameters.shadowColor
shadowColor: The color of the shadows cast by emitted light.
parameters.shadowDistance
shadowDistance: The maximum distance of the shadow starting from the position of the point
being shaded. You may use this control to artificially reduce the distance shadows are
cast. This may also increase render speed by not calculating shadows outside this distance.
parameters.shadowFalloff
shadowFalloff: the distance from the light at which shadow falloff begins.
-1.0 turns off shadow falloff. This is used along with Shadow Max Distance to create a
false fade for shadows that are reduced or cut off by the Shadow Max Distance parameter.
parameters.shadowFalloffGamma
shadowFalloffGamma: The gamma of the shadow strength in the falloff zone. This requires
the use of Shadow Max Distance and Shadow Falloff.
parameters.shadowSubset
shadowSubset: Set of geometry to consider for traced shadow intersection.
If this is not specified, all geometry are considered for traced shadow
intersection.
parameters.shadowExcludeSubset
shadowExcludeSubset: Set of geometry to ignore for traced shadow intersection.
If this is not specified, all geometry is used for traced shadow intersection.
parameters.msApprox
msApprox: Enable multi-scattering approximation. When enabled, multi-scattering approximation mimics
the effect of multi-scattering in aggregate volumes.
NOTE: Values other than 0 or 1 may produce incorrect results.
parameters.msApproxBleed
msApproxBleed: The color of the light bleed from multi-scattering approximation. Controls how much
light bleeds into the volumes illuminated by this light.
Has no effect if msApprox is set to 0.
parameters.msApproxContribution
msApproxContribution: The color of the contribution of light from multi-scattering approximation.
Controls how much the light bleed contributes to the brightness of volumes illuminated by this light.
Has no effect if msApprox is set to 0.
parameters.areaNormalize
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.
parameters.traceLightPaths
Enables light and photon tracing from this light. This value enforces a
physically-based light and as a side-effect disables thinShadow and
visibleInRefractionPath. Users may use this feature to selectively decide
which lights emit photons when using the PxrVCM or PxrUnified Integrators.
Because it will automatically disable thin shadows, this should not be
enabled when using the PxrPathTracer integrator.
parameters.thinShadow
thinShadow: Enable thin shadow and disable refraction caustics for this light.
This parameter will be ignored if Trace Light Paths is enabled. This is a
non-physical control that creates "fake" colored shadows for transmissive
objects without needing to generate photons for caustics.
Also for the paths where Cheap Caustics is enabled (surfaces marked "MWWalkable"),
then thinShadow is ignored as well.
parameters.visibleInRefractionPath
visibleInRefractionPath: Make this light source visible in refraction paths.
This parameter will be ignored if Cheap Caustics is enabled.
parameters.cheapCaustics
Enable manifold walk computation and disable thin shadow for this light.
This parameter will be ignored if Trace Light Paths is enabled.
parameters.cheapCausticsExcludeGroup
Specifies the exclude shadow subset for manifold walk. Will be used to prevent occlusion during the search of caustic path.
parameters.importanceMultiplier
Importance of this light for noise control.
parameters.lightGroup
lightGroup: Specify the light group name used for light group LPEs. This is useful to generate per-light AOVs for later adjustment in compositing.
defaultLight
Whether this light illuminates all geometry by default. When
toggled, the light will be added to the defaultLights set, which
can be referenced in set expressions and manipulated by downstream
nodes.