Raylectron is an affordable, easy and a powerful renderer for Google Sketchup.
It provide the user with 4 different rendering mode. Depending on the scene being rendered, one can use Raytrace with true shadows, Path tracing with or without direct illumination and Photon mapping. Each creating a unique effect.
One of the unique feature of Raylectron is that you are able to stop the render, save it, reopen it later and resume the render.