В хелпе на VRay (Advanced) описываются функции, которых нет в бета-версии (это то, чего так всем не хватало):
Object settings
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Generate GI - this setting controls whether VRay will trace secondary bounces for the selected objects.
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Receive GI - this setting controls the behavior of VRay raytracing while rendering GI. Turning off this option prevents VRay to evaluate GI when a ray hits the selected objects (there is no Indirect Illumination for the selected objects).
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GI multiplier - this is an additional multiplier for the GI. This value does not override the multipliers in the Indirect Illumination parameter section.
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Generate caustics - when this setting is checked the selected objects will refract the light coming from light sources that are caustics generators, so that caustics are produced. Note: in order to generate caustics an object must have a reflective or refractive material.
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Receive caustics - when this setting is checked the selected objects will become caustic receivers. When light is refracted by objects that generate caustics the resulting caustics will be only visible when they are projected on caustics receivers.
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Caustics multiplier - this value is a multiplier for the caustics generated by the selected object. Note: this value has no effect unless Generate caustics is checked.
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Так что остаётся только ждать, когда "выпустят" общедоступный бесплатный VRay Advanced..
)))