VRay for SketchUp New Features Guide
Adaptive Subdivision: This new option improves the anti-aliasing
around the edges of the geometry and on vertical and horizontal lines.
Object Outline: This option always "super-sampler" the edge of objects.
Your edges will always be sharp using Object Outline.
No Object Outline
You can see in the example above how the render without object outline
enabled has jagged edges while the render with Object Outline does not.
Randomize Sampler: This option displaces the sampler slightly to get
better anti-aliasing on horizontal and vertical lines, and avoids the unwanted
banding of edges.
Randomize Sampler Off
Randomize Sampler On
As you can see in this example, the image directly above has better
anti-aliasing and no banding edges.