Lights
The following standard Softimage light types are supported by Redshift:
- Infinite
- Light Box
- Neon
- Point
- Spot
Note Lights of type Flat are not
supported by Redshift.
The following light parameters are not applicable to Redshift or
not currently supported by Redshift:
- Light Contribution > Ambient
- All parameters under the Shadow Map tab
- Low Samples > Level, U and V
Certain light parameters are only partially supported by Redshift or may behave differently when compared to Mental Ray.
|
Exponent |
Redshift only supports inverse-square falloff (Exponent = 2). |
|
Geometry |
Object and User geometry types are not supported. |
|
Samples (U, V) |
The number of samples used for native Softimage area lights is equal to the product of U samples and V samples (i.e. Samples = U samples * V samples). |
Area Light Compatibility
Softimage light primitives allow combinations of point/spot and area types. Redshift considers them as separate types and thus limits these combinations and their meaning internally. For example, we do not support spot area lights, but instead switch from bi-directional lighting for Rectangle/Disc primitives when spot is enabled. Here are tables of Softimage light type versus area shape and what it translates to for Redshift lights:
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Shape Compatibility |
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|
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Bi-Directional? |
|
|
|
|
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Rectangle |
Disc |
Sphere |
Cylinder |
|
Rectangle |
Disc |
Sphere |
Cylinder |
|
Point |
Rectangle |
Disc |
Sphere |
Cylinder |
|
Yes |
Yes |
Yes |
Yes |
|
Spot |
Rectangle |
Disc |
Rectangle |
Rectangle |
|
No |
No |
No |
No |
|
Infinite |
N/A |
N/A |
N/A |
N/A |
|
N/A |
N/A |
N/A |
N/A |
Light Shaders
In Softimage a light consists of a light object and a one or
more connected light shaders. By default Softimage lights use the
Soft Light light shader, but other shaders such as
Portal Light (mia) can be used for special purposes.
Redshift translates Softimage lights and associated light shaders
into their Redshift equivalents allowing you to use most of the
native Softimage 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
Softimage lights whenever possible.
Supported Light Shaders
The following lists the Softimage light shaders that Redshift supports at least partially:
- Soft Light
- Portal Light (mia)
- Physical Sun (mia)
- Slide Projector
- mia_photometric_light
- mia_physicalsun
- mia_portal_light
- mib_blackbody
- mib_cie_d
Unsupported or Partially Supported Light Shaders
The following describes the Softimage light shaders and parameters which are not supported or only partially supported by Redshift with notes where applicable.
Soft Light
|
Flat Light Mode |
Not supported. |
|
Distance Attenuation |
Redshift only supports inverse-square falloff
(Light Falloff = On, Mode = Use
Light Exponent and Exponent [light parameter] =
2) or no falloff (Light Falloff
= Off). |
|
Shape Attenuation |
Not supported. |
Portal Light (mia)
|
Visible in Render |
Not supported. The visibility of the portal light is derived from the light's Visible in render parameter. |
|
Shadow Offset |
Not supported. |
|
Use Custom Environment Shader |
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. |
|
Light Cutoff Threshold |
Light cutoff values for Redshift are defined globally in the Redshift Render Options under Optimizations > Cut-off Thresholds > Shadow. |
Physical Sun (mia)
|
Photon BBox Min |
Not supported. |
|
Photon BBox Max |
Not supported. |
Fast Light Effects
The Fast Light Effects light shader is not currently supported.
Illumination
The Illumination light shader is not currently supported.
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
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photon_bbox_min |
Not supported. |
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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. |
|
visible |
Not supported. The visibility of the portal light is derived from the light's Visible in render parameter. |
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.