Layer compositing node

Layers a series of inputs together by compositing them one by one on the background image (input 1).

All

Parameters

Local variables

See also: Composite, Add, Atop, Average 9 more , Diff, Inside, Max, Min, Over, Screen, Subtract, Under, Xor

This operation does a series of composite operations (over, under, inside, add, etc.) on the background image (input 1) using the foreground images (inputs 2 and up). The compositing operation may be changed per foreground input, and each foreground input has its own transform. The first input is always the background image, and subsequent inputs are composited in order. The size of the resulting image is the size of the background image.

In the case of an over, the result image is:

4 over (3 over (2 over 1))

for four inputs, 1 to 4.

Tip

Tip: For a more traditional A over B method, use the Composite COP.

Parameters

Composite

Operation

Specifies the global compositing operation:

Over	Places the foreground over the background.
Under	Places the foreground under the background’s alpha.
Atop	Places the foreground over the background only where the background alpha exists.
Inside	Places the foreground inside the background’s alpha.
Outside	Places the foreground outside the background’s alpha.
Screen	Acts as a saturating add, much like photographic addition.
Add	Adds the foreground to the background.
Subtract	Subtracts the foreground from the background.
Diff	Takes the absolute difference between the foreground and the background.
Multiply	Multiplies the background by the foreground.
Minimum	Takes the minimum of the foreground and background.
Maximum	Takes the maximum of the foreground and background.
Average	Takes the average of the foreground and background.
Xor	Takes the exclusive or of the two alpha planes, so that alpha areas that overlap are removed.

Alpha Operation

Specifies the compositing operation for the alpha plane, which is normally the same as the global compositing operations (see above).

Image Units

Selects pixels or UV units for the transforms.

Image Filter

Specifies the filter to use when transforming.

Motion Blur

Toggles on motion blur, and specifies the time range around the current frame to blur.

Motion Frame Bias

Shifts the time range for the blur.

Motion Blur Segments

Number of samples to blur together in the specified time range.

Motion Blur Method

Velocity	Only uses the current frame and the transform to compute past and future positions.
Deformation	Cooks the images at all time samples.

Transform (1 set per foreground input)

Operation

Specifies the composite operation for this input. The default compositing operation is “global” which uses the operation specified on the Layer page.

Alpha Operation

Specifies the composite operation for the alpha channel of this input. By default, this input’s compositing operation is used (which also may point to the global compositing operation).

Image Wrap

What this input shows when data outside its image bounds is needed.

Repeat	Repeat the image again, as if tiled.
Clamp	Holds the edge pixels' values (useful for ramps).
Decal	Use black and zero alpha.
Mirror	Repeat the image again, reversing it every other time.

Translate, Rotate, Scale, Pivot

Transforms this foreground in X,Y relative to the background.

Merge

Overview	These parameters specify how to build the output sequence when there are differences between the input sequences.
Plane Merge	If the planes in the inputs differ, this specifies what the output planes should be.
Raster Depth	If the raster depth for a given plane differs between inputs, this specifies when the output raster depth for the plane should be.
Frame Range	If the frame ranges of the inputs differ, this determines what the output range should be.
Frame Rate	If the frame rates of the inputs differ, this determines what the output frame rate should be.
Frame Match	If the frame rates of the inputs differ, this determines which input frame to pick when the cook time doesn’t reside on a frame boundary.

Local variables

L	Sequence length
S	Start of sequence
E	End of sequence
IL	Input sequence length
SR	Sequence frame rate
NP	Number of planes in sequence
W,H	Width and height of image
I	Image index (0 at start frame)
IT	Image time (0 at start frame)
AI	Current plane array index
PI	Current plane index
PC	Num of channels in current plane
CXRES	Composite Project X resolution
CYRES	Composite Project Y resolution
CPIXA	Composite Project pixel aspect ratio
CDEPTH	Composite Project raster depth
CBP	Composite Project black point
CWP	Composite Project white point

Usages in other examples

Example name	Example for
MakeShadow	Pin compositing node	Load \| Launch
EnvironmentMap	Environment compositing node	Load \| Launch
StreakFlame	Streak Blur compositing node	Load \| Launch
Types	Composite compositing node	Load \| Launch