The VraySphereFade is a V-Ray specific atmospheric effect which allows you to extract and render small parts of the scene by putting them in an atmospheric gizmos.
Gizmos - holds a list of the atmospheric gizmos that are going to be affected of the VRaySpherFade atmospheric
- allows you to pick atmoshperic gizmos from the scene to add to the Gizmos list
- removes the selected gizmo from the Gizmos list
Falloff - specifies a fallof radius to blend the content in the atmospheric gizmo with the background.
Empty color - specifies the color for the background - everything outside the atmospheric gizmos
Affect alpha - when enabled V-Ray will render an alpha channel where everything outside the atmospheric gizmos will be transparent and the objects inside the gizmos will have their normal alpha