Interface

Affect Alpha

Specifies whether or not the lens flare affects the alpha channel of an image, when the image is rendered in a 32-bit file format. The alpha channel is an extra 8 bits of color (256 colors) that indicate transparency in an image. Alpha channels are used to composite one image seamlessly over the top of another. If you want to composite a lens flare, or an image that contains a lens flare, over the top of another image, enable this option. If you are not rendering to a 32-bit file, do not enable this option.

Affect Z Buffer

The Z-Buffer stores an object's distance from the camera. The Z-Buffer is useful for optical effects such as fog. When this option is enabled, the linear distance of the lens flare is recorded, and can be used in special effects that make use of the Z-Buffer, for example, the Focus effect. To use Focus with a lens flare, enable this option.

Occlusion Radius

A radius around the center of the flare that determines when the lens flare effect will begin to fade as it passes behind another object. This radius is measured in pixels.

When the lens flare or scene is animated and the source of the lens flare goes behind another object, if occlusion is enabled, the flare dies down and disappears until the source object reappears on the other side of the hiding object. The radius makes the flare gently fade when it is occluded, instead of blinking out.

Motion Blur

Determines whether or not an animated lens flare is rendered using Motion Blur. Motion Blur renders multiple copies in short increments to the same frame, which gives the illusion of a blurred object in motion. When an object is moving rapidly across the screen, it animates more smoothly if motion blur is turned on. Using motion blur can add considerable time to your rendering.

You can set the amount of blur with the Motion Blur spinner. Values range from 0 to 100, and are based on the number of samples the motion blur should use.

Axial Transparency

A standard circular transparency gradient that affects the transparency of the lens flare secondary elements along their axis and relative to their source. This lets your secondary elements be brighter on one side than the other, adding extra realism to your flare effects.

Render

Specifies whether or not each part of the lens flare is rendered in the final image. Use this set of check boxes to turn parts of the lens flare on and off.

NoteEffects such as secondary flares are available in sets. The Render button and Off Scene determine whether the secondary flares are present in the scene. The individual secondary flare sets are controlled on their respective pages.

Off Scene

Specifies whether or not lens flares that have their sources outside the scene will affect the image. For example, if a lens flare source is just off the edge of a frame, the secondary flares, and possibly the star or ring, could still be showing on the screen. Without Off Scene, the lens flare does not appear at all. You can turn this option on or off for each part of the flare.

Squeeze

Specifies whether the Squeeze setting affects a particular part of the lens flare. This setting depends on the Squeeze setting in the lens flare properties.

Inferno

Defines whether the inferno settings are active for this portion of the lens flare.

Occlusion

Defines the percentage of the flare part that appears when it is occluded by another object. A value of 100 indicates that the whole object will disappear. Lower settings cause the lens flare to wrap around the occluding object, making it fade, but not disappear entirely. For example, if you look at a cylinder with a bright light behind it, the light makes the cylinder appear thinner at the brightest areas.

NoteThe Occlusion spinners work in conjunction with the Occlusion Radius spinner in the top right of the Preferences panel.