From CollabLandWiki
This page contains information and tutorials on V-Ray that pertain to landscape architecture, architecture and urban design teaching, research and practice.
after downloading a material from the web right click in the material editor to import the material
select the material to import
to apply a material select the object, right click on the material, and select
apply material to objects
Click the
blue square to render the scene
this will bring up the V-Ray frame buffer and render the current view in Sketchup