Walker Effects Manual

Composite

The Composite plug-in is designed to perform compositing directly on a layer without the need to pre-compose. Composite is capable of taking two layers and combining them together with a number of advanced options including: inverting, masking, alpha control, and additional compositing modes.

While Composite may seem to duplicate functionality found in After Effects, it offers some very important advantages:

- Control the alpha channel behavior for any composite mode.
- Use this single plug-in instead of pre-composing with many effects.
- Stack layers multiple times without actually duplicating the layers in the Timeline Window.
- Use masking, levels, and blur all rolled into one easy to use plug-in.

View Mode

Composite provides several different View Modes to help during setup. Each View Mode will enable all relevant effect controls, while others will become disabled temporarily. Only in the Composite View Mode will all controls be active.

Background

This View Mode will display the adjusted Background layer, including all the layer options (blur, levels and masks).

Background Mask

This View Mode will display the Mask for the Background layer. If a valid path is not selected, a red X will be rendered instead.

Foreground

This View Mode will display the adjusted Foreground layer, including all the layer options (blur, levels and masks).

Foreground Mask

This View Mode will display the Mask for the Foreground layer. If a valid path is not selected, a red X will be rendered instead.

Composite

This View Mode displays the final composite of the effect. Only in this mode will all effect controls be enabled.

Background Layer

The Background Layer specifies the bottom layer to use in compositing. Often, these values are left at default so that the layer which the plug-in is on is used.

Layer

Use the layer menu to select any layer in the composition. If it is left to None, then the layer on which the effect is applied will be used.

Invert Color

Turn this checkbox on in order to invert the color channels of the layer. This can be useful in conjunction with certain Alpha and Composite Modes.

Invert Alpha

This checkbox will invert the alpha channel of the layer when enabled. Invert is calculated before Premultiply With Alpha.

Premultiply With Alpha

Enabling this checkbox will premultiply the color channels of the layer with the alpha channel. This effectively pre-renders the layer over black.

Blur

These controls provide blurring for the layer. Blur is only rendered when the amount is greater than 0. Otherwise, the group name will read 'Blur Off' and will be disabled.

Blur Quality

To help maximize rendering efficiency, this menu allows you to decide what type of blur is used. You can choose from Fast Blur or Gaussian. When set to Automatic, the effect will render the Gaussian Blur for best quality and Fast Blur for draft quality.

Uniform Blur

This checkbox controls whether the blur is applied equally in the horizontal and vertical directions. If it is turned off, separate sliders for Blur X and Blur Y will become available.

Blur After Levels

Applying blur before or after Levels can produce dramatically different results. This checkbox allows you to choose the rendering order to have maximum flexibility in using the blurring and levels features.

Levels

The Levels controls can be used to modify the grayscale values of the layer and is useful for both fine-tuning and dramatic changes. These controls work similarly to the standard Levels filter in After Effects.

Input Black

As the Input Black is increased, the channel becomes darker. Visually it appears as though the darker areas grow, eventually overtaking all pixels. The Input Black and Input White values can be moved closer together to create contrast.

Input White

Opposite of Input Black, Input White increases the range of white pixels. As the value is decreased, the brightness of the image increases until the whole image becomes white. When the Input White value is less than the Input Black, the Channel value will be inverted.

Gamma

The grayscale levels between white and black can be biased towards either end of the spectrum using Gamma. At the default value of 1.0, the interpolation from black to white is even. Gamma values less than 1.0 bias the gray levels towards black, creating a darker image with more contrast. When the Gamma value is greater than 1.0 the gray values are pushed towards white brightening the image and reducing contrast.

Output Black

The Output Black value clamps the resulting Channel value at the Output Black level. For example, if Output Black is set to a value of 45, then no pixel in the resulting Channel will be darker than 45.

Output White

Output White limits the maximum brightness of the Channel. For example, if Output White is set to 128, then no pixel in the resulting matte will be greater than 128.

Mask

Layer masks can be used with Composite similarly to how they are used in the Timeline Window by After Effects. The Mask group is only active when a valid Path is chosen. Paths must be closed. Whether the Mask is active or not is indicated by the word 'On' or 'Off' next to the Mask group name.

When Use All Paths is on, the name of the Mask group will change to reflect the current usage of paths (ie 'Mask On: Using[1,2,4]').

Important: Masks used by this plug-in should be turned off in the Timeline Window by setting their mode to None. Otherwise, the mask will be applied to the layer by After Effects as well. Furthermore, none of the mask controls in the Timeline Window are used. All settings regarding masks are controlled within the effect.

Path

To specify a mask, select the desired path from this menu. You may instead choose to Use All Paths, in which case this control will become disabled.

Use All Paths

With this option, it is not necessary to explicitly select a path. Instead, all available closed paths are used. Open paths will be ignored, while all closed paths are combined together as though they are one. The paths used are indicated by number in the name of the Mask group.

Uniform Feather

Enabling this checkbox means that mask feathering will be equal in the horizontal and vertical directions. Only one Feather slider will be provided. When this checkbox is unchecked, there will be two sliders for feather: Feather X and Feather Y. Note that the feather controls in the Timeline Window are ignored by this effect, and when using multiple paths they are all given the same feather amount.

Feather

This slider controls the size of the feathering in pixels. The feather is actually rendered by After Effects using the built-in masking tools, and will perfectly match results you get with standard masking. You can turn off Uniform Feather in order to control the feathering amount independently on the X and Y axis. In this case, to sliders will appear: Feather X and Feather Y.

Invert

When invert is on, the Mask will be rendered inverted.

Mask Mode

To control how the Mask interacts with the layer you can specify the Mask Mode. The default Mask Mode is Multiply, which produces the most commonly expected result. However, you can use any other mode to subtract, add, or otherwise affect the layer with the Mask.

Mask Opacity

The Mask Opacity controls how much the Mask affects the layer. With a value of 0, the Mask is not rendered, and at a value of 100 the Mask is fully applied. Note that Mask Opacity behaves differently than the mask opacity in the Timeline Window.

Foreground Layer

The Foreground Layer specifies the layer to composite over the Background Layer. The controls for the Background and Foreground are identical. And in fact, they are interchangeable since you can use the Composite Order Reverse option to switch the Foreground and Background. For more detailed information on each control, refer to the Background Layer documentation above.

Alpha Mode

Composite provides a number of different options for handling the compositing of alpha channels. These modes can make otherwise difficult problems easy to solve.

Normal

This Alpha Mode treats the alpha channels just as After Effects does in compositing, using the Screen operation to composite alpha channel values together. However, one big difference with compositing in Walker Effects is that the Composite Mode is respected even when compositing over a transparent background.

Alpha Only

This mode limits the operation of Composite to just the alpha channels of the layers. This make is easy to do quick alpha to alpha compositing without affecting the color channels of the Background layer. For further control, see the Channel Composite plug-in.

Luma To Alpha

This Alpha Mode will composite the Luminance of the Foreground layer into the alpha channel of the Background layer. The color channels will be unaffected.

Same As RGB

This Alpha Mode composites the alpha channel using the same Composite Mode as the color channels. This mode is useful in special case scenarios, such as when the alpha channel is being used to store data other than transparency.

Preserve Transparency

Choosing this Alpha Mode will cause Composite to keep the alpha channel of the Background Layer preserved. This means that the Foreground Layer's alpha channel will not affect the Background. This mode is often needed in situations where compositing needs to be done in the color channels only.

Alpha Add

Instead of using the Screen composite mode, Alpha Add will add the alpha channel values together. This mode is useful when you are combining images that are meant to match up perfectly. For example, when compositing 3D render passes, it is common to get slight fringing at the edges of objects due to the normal handling of alpha channels by After Effects. Using Alpha Add fixes this problem, while still allowing you to use any Composite Mode for the RGB channels.

Replace

The Replace Alpha Mode works similarly to Preserve Transparency, but preserves the alpha of the Foreground layer instead of the Background. This mode can be useful when you wish to force the alpha channel to be a certain way.

Composite Mode

This is the final composite mode used to apply the Foreground and Background layers together.

Composite Order Reverse

By enabling this checkbox, the Background and Foreground layers are swapped during compositing. In other words, the Background layer will be composited over the Foreground. This allows the layers to be interchangeable and saves in additional setup time.

Opacity

The Opacity controls how much the Foreground layer is composited over the Background. A value of 100 will fully composite the layers, while a value of 0 will leave the Background layer unaffected. Note: If using Extra Composite Modes, setting the Opacity slider to 0 will not prevent them from rendering.

Extra Composite Modes

It is not uncommon when compositing to apply the same layer multiple times. For example, you may need to Add layers together, but a single Add is not powerful enough. Other times, it is beneficial to use multiple composite modes, such as using Multiply before Color Burn. This effect allows you stack up to 3 composite modes.

Enable

To use each additional Composite Mode, you must turn on the Enable checkbox. Also keep in mind that you are not forced to use these options in order. You can turn off Composite Mode 2 and still use Composite Mode 3.

Composite Mode 2(3)

This specifies an additional Composite Mode and is only available when Enable is on.

Opacity 2(3)

This slider controls the opacity for Composite Mode 2(3). If Opacity is set to 0, then the composite mode will not be rendered.

Blend With Original

Use this slider to blend the result of the effect with the original input layer. If Blend With Original is set to 100, the effect will not render.