> ## Documentation Index
> Fetch the complete documentation index at: https://comfytv.org/llms.txt
> Use this file to discover all available pages before exploring further.

# Corner Pin

> Warp a clip by dragging its four corners — for screen replacements, sign inserts, and perspective fits.

<Frame caption="Corner Pin · screenshot coming soon">
  <img src="https://mintcdn.com/comfytv/dMkMxJDZdIo4YzAU/images/nodes/_placeholder.svg?fit=max&auto=format&n=dMkMxJDZdIo4YzAU&q=85&s=b54171099e5b02d4313fe581171ebbcc" alt="Corner Pin" width="800" height="450" data-path="images/nodes/_placeholder.svg" />
</Frame>

## What this node does

Corner Pin maps the four corners of a `COMFYTV_VIDEO` to four arbitrary destination points, applying a perspective (homographic) warp. You set the corners by dragging the four handles right on the node; the values are stored as `[[x1,y1],[x2,y2],[x3,y3],[x4,y4]]` in TL, TR, BR, BL order. It can also be animated with keyframes or driven by a corner-tracking `track` input.

It runs on **▶ Run** (renders the warp). Input and output are `COMFYTV_VIDEO`. The node errors if you haven't set four corners and there are no keyframes yet — drag the corners first.

To hand the result to a native ComfyUI node, insert a **Bridge** (`ComfyTV/Bridge`). See [https://github.com/jtydhr88/ComfyTV/blob/main/docs/bridges.md](https://github.com/jtydhr88/ComfyTV/blob/main/docs/bridges.md).

## When to use it

* Replace the content of a screen, phone, monitor, or billboard in a shot.
* Fit footage onto an angled surface with correct perspective.
* Track a moving surface and pin a layer onto it via the `track` input.

## Parameters

### corners

The four destination corners as JSON `[[x1,y1],[x2,y2],[x3,y3],[x4,y4]]` in TL, TR, BR, BL order. Normally set by dragging the four handles on the node rather than typed.

### keyframes

Advanced: JSON array `[{t, corners}]` animating the four corners over time (for a moving surface). Usually authored via the node UI.

### video (input, optional)

The `COMFYTV_VIDEO` to warp. Required.

### track (input, optional)

A `COMFYTV_TEXT` track carrying corner keyframes (e.g. from a planar tracker). When it contains corner data it overrides the manual `keyframes`.

## Outputs

| Output    | Type            | Meaning                                      |
| --------- | --------------- | -------------------------------------------- |
| **video** | `COMFYTV_VIDEO` | The corner-pinned (perspective-warped) clip. |

## Tips

* You must place four corners (or supply keyframes) before running — otherwise the node stops and asks you to drag the corners.
* Corner order is fixed: top-left, top-right, bottom-right, bottom-left. Crossed corners produce a folded/degenerate warp.

## Related nodes

* **Video Transform** — pan/scale/rotate/skew when you don't need free perspective.
* **UV Remap** — arbitrary per-pixel distortion from a UV map.
* **Video Composite** — layer the warped clip onto a background.