Seems to me whether one needs the Radiosity lighting solution is a personal choice, like all the other choices that go into an image.

It is the most realistic lighting method in Vue. If there is a place where you really should use Radiosity, i'd say indirect interior lighting (e.g. sun through window, no simulated light fixtures) is it.

Try lighting a room interior where sun through a window (no electric lighting) is simulated - with and without Radiosity and i think you'll agree. And there have been several posts here showing poor results without radiosity in the past.

In general, it will only apply where there are reflective surfaces (not dark surfaces) near each other, or where you want very realistic skylight and shadows.

"Where does GR exist in nature?" Everywhere. In the real world, most surfaces both absorb and reflect light. That reflected light can illuminate nearby surfaces and they, in turn, can light other nearby surfaces. Look around you and you'll see this hapenning nearly everywhere.

So far, only Radiosity can simulate this realistically in Vue. Global Ambience fakes it. Global Illumination fakes it better. Global Radiosity actually calculates and simulates it.

But not every scene is going to look better with Radiosity, especially if you don't sufficiently boost the ambient light in your scene.

Test it for yourself and decide if it's worth the extra render time.

_ jc...'Art Head Start' e-book
.......Art Head Start.com site Art skills for digital artists. Free lighting chapter, tutorials.