I just followed the tutorial from 'Vray for SketchUp Manual' pdf file. But when I tried the Depth of Field part, the render image didn't looks like what the tutorial said. there's no blur in it.
This is what the result should looks like:

this is what my image looks like

no blur in it
I don't know why, I've already followed everything, dof setting is turned on, override focal length, aperture, etc.
Maybe someone here would help?