5.5

151Motion User Guide
How do blend modes work in Motion?
Each blend mode presents a different method of combining (compositing) two or more
images. Blend modes work in addition to a layer’s alpha channel and opacity parameter.
To understand the descriptions of each blend mode in this chapter, it’s important to
understand that blend modes mix colors from overlapping images based on the brightness
values in each color channel in an image. Every image consists of a red, green, and blue
channel, and sometimes an additional alpha channel. Each channel contains a range of
brightness values that define the intensity of each pixel in the image that uses some of the
channel’s color.
The effect that each blend mode has on overlapping layers depends on the range of color
values in each layer. The red, green, and blue channels in each overlapping pixel are
mathematically combined to yield the final image.
These value ranges can be described as blacks, midrange values, or whites. These regions
are loosely illustrated by the chart below.
For example, the Multiply blend mode renders white color values in an image transparent,
while black values are left alone. All midrange color values become translucent, with colors
in the lighter end of the scale becoming more transparent than the colors in the darker end
of the scale.
How do blend modes affect groups in Motion?
Blend modes work differently depending on whether they’re used with groups or layers.
Pass Through
When a group is set to Pass Through (the default blend mode for groups), each layer in
the group blends with all layers and groups that appear underneath it in the Layers list—
including layers in other groups. Pass Through is available only for groups.
Important: The Pass Through blend mode is not available for 360° environments. See Intro
to graphics in 360° projects in Motion.
Normal
When a group is set to Normal, each layer in the group blends with all layers that appear
underneath it in the Layers list—within the same group.
Other blend modes
When you set a group to any other available blend mode, the following happens:
• The layers in that group are blended according their own blend modes.
• The resulting composite of all layers in that group is then blended with other groups
lower in the Layers list, according to the selected blend mode for the original group.