Native Maya Lights

Lights

The following standard Maya light types are supported by Redshift:

Directional Light
Point Light
Spot Light
Area Light

Note Ambient Light and Volume Light are not supported by Redshift.
The following light attributes are not applicable to Redshift or not currently supported by Redshift:

Illuminates by Default (All)
All attributes under the Light Effects group (Point, Spot, Area)
All attributes under the Shadows > Depth Map Shadow Attributes group (All)
Ray Depth Limit (All)
All attributes under the mental ray group – Redshift equivalents for relevant attributes are under the Redshift group

Certain light attributes are only partially supported by Redshift or may behave differently when compared to Mental Ray.

Decay Rate

Redshift only supports No Decay and Quadratic.

Redshift Attributes

Redshift automatically adds a number of attributes to native Maya lights.

Area Lighting (Area Lights Only)

Shape

Specifies the physical shape of the area light.

Rectangle
Disc
Sphere
Cylinder

Visible

Makes the area light visible to the camera (and through reflections and refractions).

Samples

Specifies the number of ray samples to use for the area light. More samples will produce smoother lighting and shadows. Generally, the larger and more intense an area light is, the more samples it needs to produce noise-free results.

Photons (All Lights)

Emit Caustic Photons	Enables caustic photon casting for the light. Has no effect if Enable Caustics is not enabled in the Redshift Render Options under the Photon Mapping tab.
Emit GI Photons	Enables GI photon casting for the light. Has no effect if Enable GI is not enabled in the Redshift Render Options under the Photon Mapping tab.
Caustic Photons	Specifies the number of caustic photons to shoot for the light.
GI Photons	Specifies the number of GI photons to shoot for the light.
Photon Color	Specifies the color of caustic and GI photons emitted by the light.
Photon Intensity	Specifies the intensity of caustic and GI photons emitted by the light.

Light Shaders (All Lights)

Light Shader	Specifies a connection to a light shader. Redshift will execute a connected light shader to compute the light intensity and color as well as the shadow color from a given point on a surface.
Photon Shader	Specifies a connection to a photonshader. Redshift will execute a connected photon shader to control the emission of photons from the light.

Light Shaders

When using Mental Ray in Maya, light shaders can be connected to lights to change their behavior.
Redshift translates Maya lights and associated light shaders into their Redshift equivalents allowing you to use most of the native Maya light features with Redshift directly. Note however that certain light shaders and/or light shader parameters are unsupported or only partially supported by Redshift. We therefore recommend using Redshift lights instead of the native Maya lights whenever possible.

Supported Light Shaders

The following lists the Mental Ray for Maya light shaders that Redshift supports at least partially:

mia_photometric_light
mia_physicalsun
mia_portal_light
mib_blackbody
mib_cie_d

Unsupported or Partially Supported Light Shaders

The following describes the Mental Ray for Maya light shaders and parameters which are not supported or only partially supported by Redshift with notes where applicable.

mia_photometric_light

units_to_meter_scale	The unit scale for Redshift is defined globally in the Redshift Render Options under Output > Photometric Units > Units To Meters Scale.
cm2_factor	The candela per meter square factor for Redshift is defined globally in the Redshift Render Options under Output > Photometric Units > cd/m^2 Factor.

mia_physicalsun

photon_bbox_min	Not supported.
photon_bbox_max	Not supported.
illuminance_mode	Not supported.
direct_normal_illuminance	Not supported.

mia_portal_light

cutoff_threshold	Not supported.
shadow_ray_extension	Not supported.
use_custom_environment	A custom environment shader will always be used if it is connected to the custom_environment input, regardless of the value of Use Custom Environment Shader.
lookup_using_fg_rays	Not supported. All environment maps will be treated as if sampled by GI rays, in order to correctly support Multiple Importance Sampling.

mib_fg_occlusion

The mib_fg_occlusion light shader is not currently supported.

mib_light_infinite

The mib_light_infinite light shader is not currently supported.

mib_light_photometric

The mib_light_photometric light shader is not currently supported.

mib_light_point

The mib_light_point light shader is not currently supported.

mib_light_spot

The mib_light_spot light shader is not currently supported.

physical_light

The physical_light light shader is not currently supported.