V-Ray for Rhino Manual - Rum

Open V-Ray Options window and pull down the Global Switches, Environment and Indirect
Illumination taps as illustrated below.
1. Global Switches
Please uncheck Hidden Lights and Default Lights
under the Lighting section.
Hidden Lights means hiding the lights from the scene.
It is used when the users don't want to see any light
while modeling in the scene. When uncheck the
Hidden Lights box, those hidden lights will not affect
the V-Ray render. To prevent these hidden lights
affect the final render output, we recommend you
uncheck the Hidden Lights first.
Default Lights means V-Ray built-in lights. Users can
not see nor edit these lights from the scene. If one
uncheck the Default Lights and does not check the GI
below, the render will turn out totally black.
We also recommend you check the Low thread
priority under the Render section so that it won't
affect other program while rendering with V-Ray.
2. Indirect Illumination
Please check the On under the GI section. That turns
the Indirect Illumination on, so called the Global
Illumination. We will explain those green dot items
more later.
3. Environment
Environment is to control the contract, color, and
HDR of the Global Illumination.
Please check the boxes before GI and Background.
Please adjust those three items then select the blue
render icon on the top. You will get the image with
Global Illumination. Compare to the image without
Global Illumination, you can see the objects don't
have dark shadow because the objects get light from
all around.
V-Ray for Rhino 11