3ds Max 2012 Bible - Kelly L. Murdock [486]
The Global Scene tabbed panel
The second Lens Effects Globals tabbed panel common to all effects is the Scene panel. This rollout includes an Affect Alpha option that lets the effect work with the image's alpha channel. The alpha channel holds the transparency information for the rendered objects and for effects if this option is enabled. If you plan on using the effect in a composite image, then enable this option.
Tip
Click the Display Alpha Channel button in the Rendered Frame Window to view the alpha channel. •
The Affect Z Buffer option stores the effect information in the Z Buffer, which is used to determine the depth of objects from the camera's viewpoint.
The Distance Affects option alters the effect's Size and/or Intensity based on its distance from the camera. The Off-Center Affects option is similar, except that it affects the effect's size and intensity based on its Off-Center distance. The Direction Affects options can affect the size and intensity of an effect based on the direction in which a spotlight is pointing.
The Occlusion settings can be used to cause an effect to be hidden by an object that lies between the effect and the camera. The Inner Radius value defines the area that an object must block in order to hide the effect. The Outer Radius value defines where the effect begins to be occluded. You can also set the Size and Intensity options for the effect. The Affected by Atmospheres option allows effects to be occluded by atmospheric effects.
Glow
The Glow Element rollout, shown in Figure 46.20, includes parameters for controlling the look of the Glow Lens Effect. This rollout has two tabbed panels: Parameters and Options.
FIGURE 46.20
The Glow Element rollout lets you set the parameters for the Glow effect.
The Glow Element Parameters tabbed panel
In the Parameters tabbed panel of the Glow Element rollout, there is a Name field. Several glow effects can be added to a scene, and each one can have a different name. The On option turns each glow on and off.
The Parameters panel also includes Size and Intensity values. These work with the Global settings to determine the size of the glow and can be set to any positive value. The Occlusion and Use Source Color values are percentages. The Occlusion value determines how much of the occlusion set in the Scene panel of the Lens Effects Globals rollout is to be used. If the Use Source Color is at 100 percent, then the glow color is determined by the light color; if it is set to any value below 100, then the colors specified in the Source and Circular Color sections are combined with the light's color.
This panel also includes Glow Behind and Squeeze options. Glow Behind makes the glow effect visible behind objects. Squeeze enables any squeeze settings specified in the Parameters panel.
If the Use Source Color value is set to 0 percent, only the Radial Color swatches determine the glow colors. Radial colors proceed from the center of the glow circle to the outer edge. The first swatch is the inner color, and the second is the outer color. The Falloff Curve button opens the Radial Falloff function curve dialog box, shown in Figure 46.21, where you can use a curve to set how quickly or slowly the colors change.
FIGURE 46.21
The Radial Falloff dialog box lets you control how the inner radial color changes to the outer radial color.
The Circular Color swatches specify the glow color around the glow circle starting from the top point and proceeding clockwise. The Mix value is the percentage to mix the Circular colors with the Radial Colors; a value of 0 displays only the Radial colors, and a value of 100 displays only the Circular colors. You can also access the Falloff Curve dialog box for the Circular Color Falloff curve.
You can also control the Radial Size using a curve by clicking the Size Curve button. Clicking the