begins to occur. Objects closer to the light than this distance receive the full intensity of light. As objects get farther than this distance, less and less light falls on them.
Fall-Off Softness
Visible: Sometimes, Default: 80%, Min: 0%, Max: 100%, Percentage This setting is only used when a object is set to be volumetric. Changes how smoothly a light falls off to the background color. A value of 0 causes an abrupt edge where the object falls off to the background color. Higher values soften the edge caused by the falloff.
Cone Angle
Visible: Sometimes, Default: 60°, Min: 0°, Max: 180°, Angle. Defines the angle of a cone shaped object.
Color
Sets the color of the light.
Intensity
Default: 100%, Percentage. This sets the brightness of the light.
Attenuation
Visible: Sometimes, Default: 100%, Min: 0%, Max: 100%, Percentage Controls how the light falls off with distance. 0% attenuation = Constant lighting with no falloff, 50% attenuation = (Linear Fall off) the light falls off proportionally to the distance to the light, 100% attenuation = (Quadratic Fall off) the light falls off proportionally to the square of the distance to the light.
Options
Contains options for how the light affects renderings.
Diffuse
Default: ON. Select this option if you want this light to illuminate objects in the scene. Deselect this option when you just want to use the light to affect specular or shadows, or if you only want to use it as a volumetric or lens flare effect.
Specularity
Default: ON. Select this option if you want this light to create specular highlights on objects in the scene.
Volumetric
Visible: Sometimes, Default: OFF. Toggles whether the selected light is volumetric or not. Volumetric lights are a popular, often seen effect of visible light beams. Volumetric lights are affected by the light’s color, width, and intensity all of which can change over time.
Quality
Default: 200%, Min: 1%, Percentage. Increase this value to decrease banding. Quality values that are too low will fail to make the effect visible. Note that higher values will increase render time.
Brightness
Default: 30%, Min: 0%, Max: 100%, Percentage. Brightness values range from 0% on up. Higher values make the effect more visible.
Contrast
Default: 50%, Min: 0%, Max: 100%, Percentage. When turbulence is used with volumetric effects, contrast values more than “50%” will make the tendrils more pronounced. Contrast values less than “50%” will de- emphasize the tendrils.
Cast Shadows
Visible: Sometimes, Default: ON. Toggles whether the selected light casts shadows or not. Shadows are important for anchoring objects in place and keeping them from appearing as if they are floating. Many shadow casting lights do not add enough detail to a scene to justify their computation time. Normally, you only need one or two shadow casting lights.
Type
Visible: Sometimes, Default: Raytraced. Shadows can be either Raytraced or Z-Buffered.
Raytraced: Raytraced Shadows take longer to render, but work with all
kinds of lights and are less prone to visual anomalies. Raytrace shadows exhibit falloff, calculated as the ratio of the distance to the shadowing object from the shadowed surface times the light’s width divided by the distance to the light. This falloff is automatic. If you want no falloff for a raytraced shadow, set the light’s “Width” to “0”. The effect of this is that the shadow gets lighter as it gets further from the object.
Z-Buffered: If the selected light source is a Klieg type light, the “Z-Buffered
Soft Shadows” option will become available.
The way z-buffer shadows work is the computer automatically renders the choreography from the light's point of view, then as the camera renders the same scene, it compares the shadow's depth against the camera's depth on each pixel to determine which of the two is closer - if the shadow buffer depth is closer, then the camera sees a shadow. Though this process sounds simple, in actuality it causes many practical problems. For one, only klieg lights can create shadow buffers because they are the only kind of light that operates similar to a camera. Second, the resolution that the light renders at had better be close to the camera's resolution or discrepancies start occurring - this precludes using a single klieg light to cover a whole scene because shadows created by such a wide, all-encompassing angle often are little more than tiny spots and the camera cannot accurately compare depths.
Z-buffer shadows also have the peculiar habit of causing visible artifacts, called “self-shadowing” (making the shadows more blurry makes the self- shadowing less objectionable). Also, z-buffer shadows tend to cut-off abruptly when the objects they are rendering across the boundaries of the
100
light's visibility rectangle.
Z-buffer shadows do not recognize Boolean operations, and transparent objects are only approximated.
If you want to use z-buffer shadows you must become an expert in overcoming their limitations, sometimes on a frame-by-frame basis. For all of their disadvantages, z-buffer shadows are usually very fast and look good.
Rays Cast
Visible: Sometimes, Default: 1, Min: 1, Max: 100. “Rays cast” is used to add penumbras to raytrace shadows “1”. Depending how large the penumbra of the shadow will be (the soft region caused by the light's width and distance from the object), the “Rays cast” setting may have to be as high as “32”. For speed, you will have to experiment to find the minimum number of rays cast - too few rays will cause the shadow to appear grainy. Klieg lights can use the “Penumbra” light setting (so leave “Rays cast” set to “1”.
Bias
Visible: Sometimes, Advanced, Default: 0.05cm, Min: 0cm, Unit of Measurement. Scenes using geometry that represent very large sizes may experience math precision errors during rendering (the visual symptom can be unwanted speckles in raytraced shadows). It may be necessary to increase the Shadow Bias Value to reduce the ray intersection precision. Values as high as 100 may be necessary.
Softness
Visible: Sometimes, Default: 25%, Min: 0%, Max: 100%, Percentage This slider controls how soft Z-Buffered shadows will look.
Darkness
Visible: Sometimes, Default: 80%, Min: 0%, Max: 100%, Percentage The darkness of all shadows. Smaller values make the shadow appear washed-out, as if light is coming from many directions.
Tint
Visible: Sometimes. Raytrace shadows are colored if they result from colored transparent objects, but are black otherwise. Zbuffer shadows, are created via another technique which allows you to specify a color that may have no connection with any object or light in the scene. For example, bright blue shadows may be cast by a white light. Colored shadows used in this manner can give the rendering a “warm” feeling (dark autumn-colored shadows of orange and red), or stylized for art’s sake, and colored shadows are very common in “anime” style rendering with toon lines and toon shading.
Use this color chip to set the shadow color. This color is mixed with the underlying color depending on the shadow Darkness.
Map Resolution
Visible: Sometimes, Default: 512x512. Selects the resolution of the shadow
map. Smaller sizes are faster. Larger sizes are only needed if you see blocky artifacts the shadows.
Bias
Visible: Sometimes, Advanced, Default: 1cm, Min: 0cm, Unit of Measurement
Increase the Shadow Bias Value if you are seeing banding in the z-buffered shadows on objects. Try to keep it between 2 and 4.
Scenes that use geometry that represent very large sizes may experience math precision errors during rendering (the visual symptom can be unwanted speckles in raytraced shadows). It may be necessary to increase the Shadow Bias Value to reduce the ray intersection precision. Values as high as 100 may be necessary.
Penumbra
Visible: Sometimes, Default: OFF. Shadows will have penumbras, lightening as they get further away (but the render time is significantly increased.) Object shading will also be affected. Light width and distance away controls the effect.
Lens Flare
Read-Only on Instance, Default: OFF. See Lens Flares.
Light Default Models
Visible: Instance Only, Default: ON. "ON" means that this light will light models with out light lists. "OFF" means that only models with this light in its light list will be light by this light. . See also Light Lists
File Info
Visible: Cache Only. See File Info property.
Light Gels
The light through a rain splattered window projects ghostly images of raindrops and rivulets into a room; light through stained glass carries with it the vibrancy of the colored panes; and the underwater caustics due to rippling waves overhead in a pool scene are easily simulated with a light gel.
To add an image to a light, simply right-click (Control-click on a Mac) in a Choreography window, or on the “Shortcut to” Light item under the choreography in the “Choreographies” section of the Project Workspace, and pick [New][Rotoscope]. You will then have the opportunity to select the image you wish to use.
If a gel is on the light, the color of the volumetric is likewise affected. This means that if you have a scene with a stained-glass window, you could select the stained-glass image as a light gel and the volumetric shafts will show the colors of the gel.
Materials can also be used as light gels. The material colors will be projected onto everything the light touches, and will color the light’s