Optical light effects
In the real world, when light shines directly into an observer's eye or into a camera's lens, the light source may appear to glow. If the light passes through a mesh (for example, a star filter on a camera) or through hair or eyelashes, the light will refract, producing a star-like glow. In some cases, the light may reflect off the surfaces of a camera's compound lens and produce a lens flare. These are all examples of optical light effects.
In Maya, when light shines directly into the camera, the light source does not, by default, glow or produce a lens flare. You can, however, add an optical effect to any light, and control which lights will produce a glow or lens flare.
There are three basic types of optical light effects: glows, halos, and lens flares. By setting the properties of each basic optical light effect, you can simulate many different types of real-world effects.
This section contains the following topics:
Creating optical light effects |
You create an optical light effect by adding it to an existing light (see "Creating lights" on page 44). A light that produces an optical light effect can produce any combination of glow, halo, and lens flare.
Note When you render a scene that contains optical light effects, the optical light effects will appear in the rendered image after all other elements in your scene have rendered. |
To add an optical light effect to a light:
- 1
- Select the light you want to produce an optical light effect.
- 2
- In the Light Effects section of the light's Attribute Editor, click the map button beside the Light Glow attribute.
- Maya automatically creates an optical FX node, connects it to the light node, and displays its Attribute Editor.
In the real world, glows have many properties that define how they look.
In Maya, you change the properties of a glow by setting the attributes of its optical FX node.
The properties of glows can be grouped into five basic categories.
 | Color, brightness, size, and opacity All glows have a specific color, brightness, size, and opacity. See "Color, brightness, size, and opacity" on page 79. |
 | Location A glow appears at the location of the light source. See "Location" on page 80. |
 | Brightness decay A glow's brightness is strongest at the light source and decreases or decays further away from the light source. (In some cases, the color of the glow may also change.) See "Brightness decay" on page 80. |
 | Glow beams A glow can consist of regularly spaced or randomly spaced beams or rays of light. These beams simulate refractions caused by a camera's star filter or by eyelashes. See "Glow beams" on page 81. |
 | Randomness A glow can either be perfectly round or blobby and uneven. See "Randomness" on page 81. |
Color, brightness, size, and opacity
 | Color To change the color of a glow, adjust the Glow Color attribute. |
 | Brightness To change the brightness of a glow, adjust the Glow Intensity attribute. |
 | Size To change the size of a glow, adjust the Glow Spread attribute. |
 | Opacity To change the amount that a glow obscures objects, adjust the Glow Opacity attribute. |
Location
Brightness decay
 | Linear brightness decay To make the brightness of a glow decrease quickly with distance, set the Glow Type attribute to Linear. |
 | Exponential brightness decay To make the brightness of a glow decrease gradually with distance, set the Glow Type attribute to Exponential. |
 | Ball brightness decay To make a glow appear as a bright, well-defined disk with sharp edges, set the Glow Type attribute to Ball. |
 | Lens flare brightness decay To make a glow appear as a series of colored disks, set the Glow Type attribute to Lens Flare. |
 | Rim halo brightness decay To make a glow appear as a colorful ring around the location of the glow, set the Glow Type attribute to Rim Halo. |
Glow beams
 | Number of regularly spaced beams To change the number of regularly spaced glow beams, adjust the Star Points attribute. |
 | Width of regularly spaced beams To change the width of regularly spaced glow beams, adjust the Glow Star Level attribute. |
 | Brightness of randomly spaced beams To change the brightness of randomly spaced glow beams, adjust the Glow Radial Noise attribute. |
 | Width and number of randomly spaced beams To change the width and number of randomly spaced glow beams, adjust the Radial Frequency attribute. (Make sure Glow Radial Noise is not 0.) |
 | Beam rotation To rotate regularly spaced or randomly spaced glow beams, adjust the Rotation attribute. |
Randomness
 | Randomness strength To change the randomness of a glow, adjust the Glow Noise attribute. |
 | Randomness rotation To rotate a glow's randomness, adjust the Rotation attribute. |
 | Randomness resizing To resize a glow's randomness, adjust the Noise Uscale and Noise Vscale attributes. |
 | Randomness movement To move a glow's randomness, adjust the Noise Uoffset and Noise Voffset attributes. |
 | Randomness contrast To change the contrast of a glow's randomness, adjust the Noise Threshold attribute. |
In the real world, halos have many properties that define how they look.
In Maya, you change the properties of a halo by setting the attributes of its optical FX node.
The properties of halos can be grouped into three basic categories.
Color, brightness, and size
 | Color To change the color of a halo, adjust the Halo Color attribute. |
 | Brightness To change the brightness of a halo, adjust the Halo Intensity attribute. |
 | Size To change the size of a halo, adjust the Halo Spread attribute. |
Location
Brightness Decay
 | Linear brightness decay To make the brightness of a halo decrease quickly with distance, set the Halo Type attribute to Linear. |
 | Exponential brightness decay To make the brightness of a halo decrease gradually with distance, set the Halo Type attribute to Exponential. |
 | Ball brightness decay To make a halo appear as a bright, well-defined disk with sharp edges, set the Halo Type attribute to Ball. |
 | Lens flare brightness decay To make a halo appear as a series of colored disks, set the Halo Type attribute to Lens Flare. |
 | Rim halo brightness decay To make a halo appear as a colorful ring around the location of the halo, set the Halo Type attribute to Rim Halo. |
Properties of lens flares |
In the real world, lens flares have many properties that define how they look.
In Maya, you change the properties of a lens flare by setting the attributes of its optical FX node.
The properties of lens flares can be grouped into four basic categories.
Color and brightness
 | Color To change the basic color of a lens flare, adjust the Flare Color attribute. |
 | Color range To change the color range of a lens flare, adjust the Flare Col Spread attribute. |
 | Brightness To change the brightness of a lens flare, adjust the Flare Intensity attribute. |
Location
Shape, size, sharpness, and number
 | Shape To change the shape of a lens flare to a hexagon, turn on the Hexagon Flare attribute. |
 | Size To change the size of a lens flare, adjust the Flare Min Size and Flare Max Size attributes. |
 | Sharpness To change the sharpness of a lens flare, adjust the Flare Focus attribute. |
 | Number of elements To change the number of elements (circles or hexagons) in a lens flare, adjust the Flare Num Circles attribute. |
Spread length and spread direction
 | Spread direction To change the direction of a spread lens flare, adjust the Flare Vertical and Flare Horizontal attributes. |
 | Spread length To change the spread length of a lens flare, adjust the Flare Length attribute. |
Optical light effect icons |
When you create an optical light effect in Maya, an optical FX icon appears in camera views around the light's icon (see "Light icons" on page 50). This icon represents the position and size of the optical light effect.
Removing optical light effects |
You can temporarily turn off or permanently remove an optical light effect from a light.
To temporarily turn an optical light effect off or on:
- In the optical FX's Attribute Editor, set the Active attribute off or on.
- When Active is off, a yellow X appears in the Post Process Sample at the top of the Attribute Editor to indicate that the optical light effect will not render.
To permanently remove an optical light effect:
- 1
- Select the optical FX node.
- 2
- Press Delete.
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