Layer Source

References another layer's rendered output as a texture, enabling cross-layer connections within a composition.

Category: Source Menu path: Source > LayerSource

Ports

Port	Type	Direction	Description
out	imageRgba16f	output	The rendered output of the referenced layer

Parameters

Param	Type	Default	Description
sourceLayerId	string	""	The ID of the source layer. Selected via a dropdown in the Properties panel that lists all other layers in the composition.

How It Works

LayerSource lets one layer use another layer's fully rendered output as an input texture. The engine evaluates layers in dependency order -- if Layer B references Layer A via LayerSource, Layer A is always evaluated first. The result is the source layer's graph output (everything up to and including its Output node), mapped into the consuming layer's coordinate space with automatic overscan correction.

The source layer dropdown in Properties lists all layers in the current composition except the layer that contains the LayerSource node (to prevent self-reference). Circular dependencies (A references B, B references A) are detected during evaluation and blocked.

Caching is content-aware: the LayerSource texture only updates when the source layer's output actually changes, not on every frame. Static source layers are essentially free after the first evaluation.

Usage Examples

Basic: Reuse a layer as texture input

1. Create Layer A with some content (e.g., an animated shape or text)
2. Create Layer B with a LayerSource node
3. In the Properties panel, set LayerSource's source to Layer A
4. Connect the LayerSource output to effects in Layer B's graph (Blur, UVRemap, Tile, etc.)

Layer A's rendered output becomes a live texture input in Layer B's node graph.

Displacement map from another layer

Create a grayscale pattern or noise on one layer, then use LayerSource in another layer to feed it into UVRemap's uv_map input. The first layer acts as a displacement map that distorts the second layer's content.

Pre-compositing

Build a complex multi-node graph on one layer, then reference its output via LayerSource in several other layers. Each consuming layer can apply different effects or transforms to the same base content without re-evaluating the source graph.

Tips

• The source layer dropdown in Properties shows layer names, making it easy to identify the right target. Give your layers descriptive names.
• Matte source layers (used for track mattes) are excluded from compositing automatically. LayerSource is a different mechanism -- the referenced layer still composites normally in the layer stack unless you hide it.
• If you want the source layer to be invisible in the final composite but still available via LayerSource, disable its visibility (eye icon in the layer list).
• Circular references are caught at evaluation time. If detected, the LayerSource outputs nothing.
• LayerSource captures the full graph output of the source layer, including any effects and transforms applied within that layer's node graph.

Related Nodes

• ImageSource -- loads an image from a file instead of another layer
• VideoSource -- loads video frames from a file
• Merge -- composites two textures within the same layer's graph