Output

The compositing interface for a layer. Controls opacity, blend mode, and motion blur. Every layer's node graph has exactly one Output node.

Category: Utility Menu path: Not added from context menu (auto-created with layers)

Ports

Port	Type	Direction	Description
in	imageRgba16f	input	The layer's final image to composite into the composition

Parameters

Param	Type	Default	Description
opacity	scalar	1.0	Layer opacity (0 = transparent, 1 = fully visible)
blendMode	enum	Normal	Compositing blend mode: Normal, Add, Multiply, Screen, Overlay
motionBlur	boolean	false	Enable temporal supersampling for this layer

How It Works

Output is the terminal node of every layer's node graph. It serves as the compositing interface -- the engine reads its opacity and blend mode via resolve_output_compositing() to determine how this layer composites over the layers below it in the timeline.

Key distinction: Output has no spatial transform. Position, scale, and rotation are controlled by Transform2D nodes earlier in the chain. Output is purely about compositing (opacity and blending).

When no node is selected but a layer is active, the Properties panel shows the Output node's params as the layer's top-level properties (opacity and blend mode).

Motion blur: When enabled, the engine evaluates the layer's graph at multiple sub-frame times within the shutter window and accumulates the results. The composition's shutterAngle, shutterPhase, and samplesPerFrame settings control the temporal sampling.

Blend modes:

• Normal: Standard Porter-Duff alpha compositing
• Add: Additive blending (brightens)
• Multiply: Darkens by multiplying RGB values
• Screen: Lightens by inverting, multiplying, and inverting
• Overlay: Combines Multiply and Screen based on base layer luminance

Usage Examples

Basic: Standard layer

ImageSource -> Transform2D -> Output (opacity: 1, blendMode: Normal). The standard layer pipeline.

Semi-transparent overlay

... -> Output (opacity: 0.5, blendMode: Screen). A half-opacity screen blend for light effects.

Motion-blurred animation

... -> Output (motionBlur: true). Enable on layers with fast-moving keyframed transforms. Set composition shutter angle in comp settings.

Tips

• Every layer gets exactly one Output node -- you cannot delete it or add a second one
• Output node params appear as top-level layer properties when no node is selected in the graph
• Pasting nodes from another layer skips the Output node if the target layer already has one
• The blendMode param is a numeric enum (0=Normal, 1=Add, etc.) but renders as a dropdown in Properties
• Layer.transform and Layer.blend_mode fields are vestigial -- the engine reads from the Output node

Related Nodes

• Transform2D -- spatial transform (position, scale, rotation)
• Merge -- in-graph compositing with blend modes (vs. Output's cross-layer compositing)
• Debug -- inspect values anywhere in the graph