Barrel Distortion

Warps an image radially to simulate lens barrel (bulge) or pincushion (pinch) distortion.

Category: Effects Menu path: Effects > Barrel Distortion

Ports

Port	Type	Direction	Description
in	imageRgba16f	input	Input image
out	imageRgba16f	output	Distorted result

Parameters

Param	Type	Default	Description
amount	scalar	0.0	Distortion strength. Positive = barrel (bulge, content pushes outward); negative = pincushion (pinch, content pulls inward). Useful range ~ -1 to 1. Keyframeable.
zoom	scalar	1.0	Scales the result about the center so distorted corners stay in frame. Values above 1 zoom in (crop edges); below 1 zoom out. Keyframeable.

Expose Channels

When enabled (E button on node header), adds input ports that override params via edge connections:

Port	Type	Overrides
amount_in	scalar	amount

How It Works

For each output pixel the shader builds a centered, aspect-corrected coordinate c = uv - 0.5 (with x scaled by the comp's width/height ratio so the warp is radially symmetric on non-square comps). It computes the squared radius r2 = dot(c, c), applies the distortion c' = c * (1 + amount * r2) / zoom, undoes the aspect correction, and samples the input at 0.5 + c'. Pixels whose source coordinate falls outside the frame become transparent. All coordinate math uses the comp resolution (not the render resolution), so the result is identical across Draft / Preview / Full quality. When amount is 0 and zoom is 1 the node is a pure passthrough and the GPU pass is skipped.

Usage Examples

Basic: Lens bulge

1. Add a Barrel Distortion node after your footage or render
2. Set amount to ~0.3 for a gentle fisheye-style bulge
3. Raise zoom slightly (e.g. 1.1) to hide the transparent corners that the bulge pulls in

Creative: Pincushion correction

1. Set amount to a small negative value (e.g. -0.2) to counteract a barrel-distorted source
2. Adjust zoom to recover any cropped edges

Advanced: Animated lens breathing

1. Enable expose channels and connect an Oscillate or Time-driven Math node to amount_in
2. Animate a subtle ±0.05 wobble for a handheld / organic lens feel

Tips

• The distortion is strongest at the corners (largest radius) and near zero at the center
• Increase zoom whenever a positive amount introduces transparent corners
• Because the effect samples within the existing frame, it does not expand layer bounds — pair with a Transform2D scale-up first if you need more source coverage

Related Nodes

• UVRemap — arbitrary UV-space distortion driven by a map texture
• ChromaticAberration — per-channel fringing that pairs well with lens distortion for a realistic lens look
• Transform2D — affine scale/position/rotation without radial warping