Если я правильно понял, то речь идет о связке МАКС-МР. Вот выдержка из хелпа от коннектора:
"Raytrace map
This map simply tells the mental ray renderer to use ray-traced reflections and refractions. All Raytrace map parameters are ignored.
Caution: Don't assign a Raytrace map to a material component other than reflection or refraction. This will not render correctly.
Reflect/Refract map
This map tells the mental ray renderer to use ray-traced reflections and refractions. Most parameters are supported, but the parameters Blur Offset, First Frame Only, Every Nth Frame, and Atmosphere Ranges are not."
В принципе, можно было и самому прочесть, не так ли?
"Raytrace map
This map simply tells the mental ray renderer to use ray-traced reflections and refractions. All Raytrace map parameters are ignored.
Caution: Don't assign a Raytrace map to a material component other than reflection or refraction. This will not render correctly.
Reflect/Refract map
This map tells the mental ray renderer to use ray-traced reflections and refractions. Most parameters are supported, but the parameters Blur Offset, First Frame Only, Every Nth Frame, and Atmosphere Ranges are not."
В принципе, можно было и самому прочесть, не так ли?