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Copy

Replaces channels in the B input with channels from the A input. You can use a mask channel to indicate which input is used for each pixel or whether both inputs should be mixed for some pixels.

Using the mix slider, you can use this node as a dissolve.

You can also create this node by pressing K on the Node Graph.

Inputs and Controls

Connection Type	Connection Name	Function
Input	A	The image that contains a channel to copy to input B.
	B	The image that contains a channel to replace with a channel from the A input.
	mask	An optional image to use as a mask. By default, the A input is used where the mask is white, the B input where the mask is black, and a blend between the inputs where the mask is gray. At first, the mask input appears as triangle on the right side of the node, but when you drag it, it turns into an arrow labeled mask. If you cannot see the mask input, ensure that the mask control is disabled or set to none.

Control (UI)	Knob (Scripting)	Default Value	Function
Copy Tab
Copy channel	N/A	enabled	Enables the associated channel to the right. Disabling this checkbox is the same as setting the channel to none.
Copy channel	from0	rgba.alpha	A channel to copy from input A.
to	N/A	enabled	Enables the associated channel to the right. Disabling this checkbox is the same as setting the channel to none.
to	to0	rgba.alpha	The channel that the above Copy channel replaces in input B.
Copy channel	N/A	enabled	Enables the associated channel to the right. Disabling this checkbox is the same as setting the channel to none.
Copy channel	from1	rgba.alpha	Another channel to copy from input A.
to	N/A	enabled	Enables the associated channel to the right. Disabling this checkbox is the same as setting the channel to none.
to	to1	rgba.alpha	The channel that the above Copy channel replaces in input B.
Copy channel	N/A	enabled	Enables the associated channel to the right. Disabling this checkbox is the same as setting the channel to none.
Copy channel	from2	rgba.alpha	Another channel to copy from input A.
to	N/A	enabled	Enables the associated channel to the right. Disabling this checkbox is the same as setting the channel to none.
to	to2	rgba.alpha	The channel that the above Copy channel replaces in input B.
Copy channel	N/A	enabled	Enables the associated channel to the right. Disabling this checkbox is the same as setting the channel to none.
Copy channel	from3	rgba.alpha	Another channel to copy from input A.
to	N/A	enabled	Enables the associated channel to the right. Disabling this checkbox is the same as setting the channel to none.
to	to3	rgba.alpha	The channel that the above Copy channel replaces in input B.
Layer Copy	channels	none	Copies all the selected channels from A to B, if they exist in A. If they don’t exist in A, the channels from B are used unchanged. This allows you to easily copy multiple channels from A to B. For example, setting this to all copies all the channels that exist in A. If you set this to something other than all or none, you can use the checkboxes on the right to select individual channels.
Set BBox to	bbox	union	How to output the bounding box: • union - combine the two bounding boxes. • B side - use the bounding box from input B. Any data from the A input that’s outside this box is clipped. • A side - use the bounding box from input A. Any data from the B input that’s outside this box is clipped.
mask	N/A	disabled	Enables the associated mask channel to the right. Disabling this checkbox is the same as setting the channel to none.
mask	maskChannelInput	none	The channel to use as a mask. By default, the A input is used where the mask is white, the B input where the mask is black, and a blend between the inputs where the mask is gray.
inject	inject	disabled	Copies the mask input to the predefined mask.a channel. Injecting the mask allows you to use the same mask further downstream.
invert	invert_mask	disabled	Inverts the use of the mask channel so that the B input is used where the mask is white and the A input where the mask is black.
fringe	fringe	disabled	Blurs the edges of the mask.
(un)premult by	N/A	disabled	Enables the associated channel to the right. Disabling this checkbox is the same as setting the channel to none.
(un)premult by	unpremult	none	The image is divided by this channel before being processed, and multiplied again afterwards. If you are using premultiplied input images, you may want to check (un)premult by and select rgba.alpha here. This will simulate doing the copy before the premultiplication was done. It is the same as adding an Unpremult node before this node and a Premult node after, but allows you to work faster if you’re only using one Copy node. If you are using unpremultiplied input images, you should leave this set to none.
invert	invert_unpremult	disabled	Inverts the use of the (un)premultiply channel.
mix	mix	1	Dissolves between the original B input at 0 and the full copy effect at 1.