Fix: Godot 4 Shader Canvas Light Occluder Extra Shadow Frame

Wall moves; shadow follows one frame later. Visible at slow movement.

Sync occluder updates

Connect Process to LightUpdate; emit signal; light re-renders.

Or process per frame

ProcessMode = ProcessMode.ALWAYS on light; renders every frame.

Verify timing

Pause-frame inspection: occluder position vs shadow position. One-frame gap = the bug.

“Lights and occluders may have different update cadences. Sync them.”

For dynamic 2D shadows, the sync pattern is mandatory. Plan it.

Related reading

• Fix: Godot 2D Light Shadow Acne On Tilemap
• Fix: Godot Shader Canvas Light Mode Misses Secondary Lights
• Fix: Godot Shader Canvas Light Cancel After Mask Changes
• Fix: Godot Shader Canvas 2D Light Not Affecting