Setting Light Properties
You can set several light properties in the Light Controls, but an extended set of properties is available in the Properties panel, as shown in Figure 7-6. The Name field lists the light's name, which is simply Light and a number by default, but you can type a new name.

The Preview panel in the Document Window can display real-time lighting effects for up to eight lights. By default, the eight brightest lights are displayed, but you can selectively set which lights are displayed by enabling the Include in OpenGL Preview option.

 New Poser 8 Feature
The Include in OpenGL Preview option is new to Poser 8.

The Visible property makes the visual icon of the light appear in the Document Window, the Animating property enables the light to be animated, and the On property turns the light on and off. The Properties palette also includes a set of radio buttons for selecting the light type and controls for configuring the shadows, ambient occlusion and attenuation. Shadows and ambient occlusion is covered in the next section.

Setting Light Attenuation
For Spot and Point lights, you can select an Attenuation setting. This setting controls how the intensity of the light decreases the further you move from the light source. This is a realistic effect that occurs in real-life. The options include Constant, Inverse Linear, and Inverse Square. The Constant option has no decrease and works just like lights in previous Poser versions; the Inverse Linear option decreases linearly with distance; and the Inverse Square option decreases exponentially so that objects close to the light source get much more light than those further away. Figure 7-7 shows a single point light with each of the attenuation options enabled.

 New Poser 8 Feature
The various light attenuation options are new to Poser 8.

Setting Light Parameters
In addition to the settings in the Properties palette, there are several more values in the Parameters palette for controlling lights. For Spot and Point lights, you can set the Distance Start and Distance End values, which denote the distance from the light’s center where the light starts to decay and the distance where the light has diminished to zero. For spotlights, you can also set Angle Start and Angle End values, which are the strength of the light at the cone’s point and the strength of the light at the end of the cone.

The Parameter palette also includes settings for controlling the intensity of the enabled shadows with the Shadow parameter. A value of 0 turns off shadows and higher values gradually darken the shadow until a value of 100, which is maximum. The Map Size is used to specify the size of the bitmap in pixels of the shadow map. Larger shadow maps have a finer resolution, but require more memory.

The Red, Green, Blue, and Intensity values set the light’s color and power. These parameters work the same as the settings found in the Light Controls.