MergeExpression

Per-channel expressions of A and B.

raw .mdPress ? for keys

Node	MergeExpression
Menu	Merge › MergeExpression
Names in each format
.oink comp (JSON)	`"type": "OC_N_mergeexpression"`
.nk script	`MergeExpression` (how .nk import works)
Python	`nuke.createNode("MergeExpression")`
Assistant (MCP)	`create_node(type="MergeExpression")`
Tab search	`mergeexpression`, or its initials `me`

MergeExpression properties

Inputs and outputs

Port	Name	Type
input 0	B	image
input 1	A	image
input 2	mask	image
output 0	Image	image

Knobs

Panel tab Mergeexpression, in panel order.

Knob	Label	Type	Default	Range / values	.nk knob	Description
`temp_name0`	temp_name0	text			`temp_name0`
`temp_expr0`	temp_expr0	text			`temp_expr0`
`temp_name1`	temp_name1	text			`temp_name1`
`temp_expr1`	temp_expr1	text			`temp_expr1`
`temp_name2`	temp_name2	text			`temp_name2`
`temp_expr2`	temp_expr2	text			`temp_expr2`
`temp_name3`	temp_name3	text			`temp_name3`
`temp_expr3`	temp_expr3	text			`temp_expr3`
`channel0`	channel0	text	`rgba.red`		`channel0`
`expr0`	= expr0	text			`expr0`
`channel1`	channel1	text	`rgba.green`		`channel1`
`expr1`	= expr1	text			`expr1`
`channel2`	channel2	text	`rgba.blue`		`channel2`
`expr2`	= expr2	text			`expr2`
`channel3`	channel3	text	`rgba.alpha`		`channel3`
`expr3`	= expr3	text			`expr3`
`mask_channel`	mask	menu	`none`	none, rgba.alpha, rgba.red, rgba.green, rgba.blue		Mask channel, e.g. rgba.alpha (none = no mask)
`inject`	inject	bool	`false`			Copy the mask into mask.a for nodes downstream
`invert_mask`	invert	bool	`false`		`invert_mask`
`fringe`	fringe	bool	`false`			Only apply the effect at the edges of the mask
`unpremult`	(un)premult by	menu	`none`	none, rgba.alpha
`invert_unpremult`	invert	bool	`false`			(Un)premultiply by 1 - alpha
`mix`	mix	float	`1`	0 to 1	`mix`

Other knobs (Python, .nk and the assistant; not on the panel)

Knob	Label	Type	Default	Range / values	.nk knob	Description
`gl_color`	Viewer Controls Color	float ×3	`0, 0, 0`	0 to 1
`postage_stamp_frame`	Static Frame	int	`1`	-2147483648 to 2147483647
`lifetimeStart`	Lifetime Start	int	`0`	-2147483648 to 2147483647
`lifetimeEnd`	Lifetime End	int	`100`	-2147483648 to 2147483647
`useLifetime`	Use Lifetime	boolean	`false`
`cached`	Cached	boolean	`false`
`bookmark`	Bookmark	boolean	`false`
`dope_sheet`	Dope Sheet	boolean	`false`
`clone_group`	Clone Group	string
`link_source`	Link Source	string
`link_overrides`	Link Overrides	string
`split_views`	Split Views	string
`channels`	Channels	string	`rgba`			Layer the op applies to: rgb, rgba, alpha, all, none, <layer> or <layer>.<ch>

Merge

Layers the A input with the B input using the chosen operation (30 operations, over by default).

Premult

Multiply colour by alpha.

On this page

Inputs and outputs Knobs Other knobs (Python, .nk and the assistant; not on the panel)