These are descriptions of the options in the mental ray section of the FurFeedbackShape node. These mental ray settings are used when the fur object is rendered in mental ray.
Uncheck this option so that the fur object is not be visible if behind another, transparent object.
Uncheck this option so that transparency rays do not transmit through the fur object and treat the object as if it were opaque.
Uncheck this option so that the fur object does not contribute any light to final gather.
Uncheck this option so that the fur object does not receive any final gather light.
Use the Min Sample Level and Max Sample Level attributes to set the range of samples used for the fur object. Note that the min and max sample level values set for the fur are bound by the global min and max sample level values, found in the Render Settings dialog. See Anti-Aliasing Quality for more information regarding the global sample level values.
This is the minimum number of samples per pixel used when processing an image, specific to the fur object. This value is clamped to the global min sample level value. For example, if the fur-specific min sample level is set to -1 and the global min sample level is set to 1, then the global setting of 1 will be used. Based on Contrast Threshold(adaptive) settings, mental ray for Maya will increase these samples as needed.
This is the maximum number of samples per pixel used when processing an image, specific to the fur object. This value is clamped to the global max sample level value. For example, if the object-specific max sample level is set to 3 and the global max sample level is set to 2, then the global setting of 2 will be used.
This attribute controls the rasterizer’s shading samples for the fur object only. See Render Settings: mental ray tabs for more information about the rasterizer.
When on, you can set fur-specific final gather options to override the global final gather settings that you have set in the Render Settings window.
Controls how many rays are shot in each final gathering step to compute the indirect illumination. The default is 1000 per sample point, but this tends to be high for test renders (renders can take hours). Test rendering at lower values, usually 100 or 200, is sufficient; higher values are required for final renders. Increasing the value reduces noise but also increases the rendering time. The setting for Final Gather Rays uses the ghosting settings from Windows > Settings/Preferences > Preferences > Display > Animation.
Max Radius and Min Radius control the size of the sampling region within which Final Gather rays search for irradiance information from other surfaces.
With the default values, Maya calculates values that seem appropriate based on scene dimensions to speed up the render, but this calculation doesn’t allow for complex geometry. Generally, enter a value that is 10% of scene’s overall dimension for the Max Radius, then enter 0.0 for Min Radius. Make further adjustments based on scene geometry detail, how the geometry is arranged in the scene, and how the render looks. For example, use smaller radii to achieve better detailing in nooks and crannies in your scene.
This option causes the Min Radius and Max Radius of final gather rays to be calculated in pixel size, rather than in object space. This allows you to set the visual quality in pixel size, without knowing the object or scene bounds.
Use this to control how Final Gather uses a speckle elimination filter to prevent samples with extreme brightness from skewing the overall energy stored in a Final Gather sampling region.
Neighboring samples are filtered so that extreme values are discarded in the filter size. By default, the filter size is 1. Setting this to 0 disables speckle elimination, which can add speckles but will better converge towards the correct total image brightness for extremely low accuracy settings. Size values greater than 1 eliminate more speckles and soften sample contrasts. Sizes greater than 4 or so are not normally useful.
When enabled, you can set fur-specific global illumination options to override the global global illumination settings that you have set in the Render Settings window.
Change the number of photons used to compute the local intensity of global illumination. The default number is 64; larger numbers make the global illumination smoother but increase render time.
Controls the maximum distance at which mental ray for Maya considers photons for global illumination. When left at 0 (the default), mental ray for Maya calculates an appropriate amount of radius, based on the bounding box size of the scene. If the result is too noisy, increasing this value (to 1 to start, then by small increments up to 2) decreases noise but gives a more blurry result. To reduce the blur, you must increase the number of global illumination photons (Global illumination Accuracy) emitted by the light source.
When enabled, you can set fur-specific caustics options to override the global caustics settings that you have set in the Render Settings window.
Controls the number of photons used to estimate the caustic brightness. The default is 64. Higher settings (up to 100 to start, tested in small increments) make the caustic smoother.
Controls the maximum distance at which mental ray for Maya considers photons for caustics. When left at 0 (the default), mental ray for Maya calculates an appropriate amount of radius, based on the bounding box size of the scene. If the result is too noisy, increasing this value (to 1 to start, then by small increments up to 2) decreases noise but gives a more blurry result. To reduce the blur, you must increase the number of caustic photons (Caustic Accuracy) emitted by the light source.
When enabled, you can set fur-specific maximum displacement options to override the global Max Displace settings that you have set in the Render Settings window.
Specifies the maximum displacement applied to object control points in a normal direction. This provides control over the otherwise automated displacement range to better focus tessellation where most needed. Set this value if you have any displaced objects in your scene. See mental ray Overrides for more information.