The Merge Node

The Merge node is the most frequently used node in Oraphim's compositor. It is the mathematical engine that calculates how two images should be combined.

The Anatomy of a Merge

A standard Merge node has three distinct inputs:

1. Yellow Input (Background): This is the canvas. The Merge node inherits the resolution and aspect ratio of whatever image is plugged into this yellow input.
2. Green Input (Foreground): This is the image placed on top of the background. If the foreground image has transparency (an Alpha channel), the background will be visible underneath.
3. Blue Input (Effect Mask): This optional input accepts a grayscale image (like a polygon shape) that dictates where the merge is allowed to happen.

Transform Controls within the Merge

You do not always need a separate Transform node to move a foreground element. The Merge node's Inspector panel includes built-in controls specifically for the Foreground image.

Select a Merge node and look at the Inspector:

• Center X/Y: Moves the foreground image.
• Size: Scales the foreground image up or down.
• Angle: Rotates the foreground image.

Note: These controls only affect the Green input (Foreground). The Yellow input (Background) remains completely unaffected.

Apply Modes (Blend Modes)

By default, the Merge node operates in "Normal" mode—the foreground simply covers the background. However, you can change the mathematics of how the two images combine using the Apply Mode dropdown in the Inspector.

Common Apply Modes:

• Screen: Drops the black values of the foreground, keeping only the bright pixels. Excellent for compositing fire, smoke, and lens flares.
• Multiply: Drops the white values, keeping only the dark pixels. Excellent for compositing shadows or dirt.
• Overlay: Increases contrast by multiplying dark pixels and screening light pixels.

The Blend Slider

At the top of the Merge node's Inspector is the Blend slider. This acts as the master opacity for the merge operation.

• A Blend of 1.0 means the foreground is 100% visible.
• A Blend of 0.0 means the foreground is 0% visible (invisible).
• By adding keyframes to the Blend slider, you can easily create custom fade-in and fade-out animations.

Use Merge in a production project

1. Open Composition workspace and select the intended layer, mask, matte, effect, or composition graph item.
2. Establish the correct input state first—timing, media link, layer/node enable state, project settings, or source selection as relevant.
3. Apply or adjust Merge with one clear goal. Change the smallest set of controls needed to reach that goal so the result remains understandable and reversible.
4. Review the complete affected range in context. Scrub difficult frames and also play at normal speed when motion or audio is involved.
5. Save a named milestone before moving into another major operation, especially after graph changes, tracking, AI processing, relinking, simulation, or delivery setup.

Practical guidance

A merge combines foreground/background image branches. Check input order, alpha, transform, blend behavior, and premultiplication when edges look wrong.

A useful test is a short 5–10 second section containing both an easy case and a difficult case for this feature. Tune against the difficult moment without breaking the easy one. If two approaches are plausible, duplicate/version the project state and compare them rather than stacking both together blindly.

Verify the result

• Scrub the shot, inspect edges and timing, then render a short review range.
• Toggle/bypass the operation where possible and make sure the change you intended is actually responsible for the result.
• Check selection, visibility/mute/solo state, node connections, track locks, range, and source identity when the result appears missing.
• Save and reopen before treating a complex setup as reusable.
• If this feature changes final pixels or audio, render a short review and inspect the file outside Oraphim.

Related guides

• Adjustment Layers
• Effects
• Compositing Overview
• Layers