Lighting an Interior Daytime Scene - Photographic Rendering with V-Ray for SketchUp - page 50

Sunlight is our key light

The place to start when working on any kind of lighting design is to decide exactly
what will constitute the key light in the environment. This is the light that provides the
main source of illumination for the render and is also, generally speaking, the main
shadow casting light.

In a daylight setting, it doesn't take a lot of figuring to realize that our key light would
most likely be the Sun. The question is, which of the available V-Ray light types should
we be using as our Sun? This, I suppose, could seem like a silly question given that
we have already highlighted the availability of the V-Ray Sun light type.

Well, V-Ray does offer other light types that could almost as easily be used as a sun-
light in the scene. In V-Ray Version 2.0, we have the Omni, Rectangle, Spot, Dome,
Sphere, and IES light types, which are all readily available at the click of a button in
the VfS:Lights toolbar.

The beauty of these particular light objects is that they are free of the inherent restric-
tions and limitations that come with the V-Ray Sun, given that it has been designed to
be a physically accurate light source. This means that the position of the V-Ray Sun
in a scene can only be set according to what is physically possible in the real world
given a particular time of day at a particular time of year.

SketchUp shadow settings - positioning the

V-Ray Sun

To demonstrate the possible difficulties this could present, let's close any open dia-
logue windows and then open up the SketchUp's shadow settings window by perform-
ing the following steps:

1. Left-click on the Window menu at the top of the SketchUp UI.
2. Select the Shadows option from the drop-down menu.