There are two ways to position a light. The first, and most intuitive, way is to interactively position the light by dragging it to the desired location in the lighting panel. Lights move in a sphere around the test sphere. Experiment with the motion until you are comfortable moving the light. The second way to move the light is to type a direction vector into the Direction text field. The coordinate system for specifying a direction vector is right-handed. Suppose you want to create a light that looks directly into the visualization. Since the Z-axis points directly out of the screen, the negative Z-axis points into the screen. This can be captured by entering a direction vector of: 0 0 -1. Note that ambient lights have no direction.