ANR Card To Track

Overview

Card To Track projects a Card through its camera on every frame and hands the result back as ordinary 2D nodes. Copy Tracker makes a Tracker with one track per corner (bottom-left, bottom-right, top-right, top-left, and optionally the centre). Copy CornerPin makes a CornerPin keyed on every frame, in one of four ways: pin an image onto the card, flatten the card's area back out, or match-move or stabilise from a Reference Frame.

Use it when a camera solve or a 3D layout already tells you where a surface is, and you want to do the rest of the work in 2D: paint on a flattened wall, pin a screen insert, or drive a 2D tool that needs a track. A CornerPin of the card's own texture lands exactly where the ScanlineRender draws the card.

The node can also output the card's shape as a matte, live, without any button.

Inputs

1. Sourceoptional

   The plate. It sets the format the tracks and pins are in, and is what the node shows. Without it, the ScanlineRender's format (or the project format) is used.

2. Sceneoptional

   The ScanlineRender (or RayRender) that renders your Card, or a node below it. The node reads the Card and the camera from that render. Card Number picks one Card when the scene holds several.

3. Cameraoptional

   A Camera. Overrides the camera of the Scene input. With a Camera here you can skip the Scene input and pick the Card with Use Selected Card.

Output. The plate, untouched, with the card's corners drawn in the viewer. Output can also give the plate with the card's shape as alpha (Source + Card Alpha) or the card's shape, white on black (Card Matte).

Quick start

1. Add ANR Card To Track and connect the plate to Source.
2. Connect the ScanlineRender that renders your Card to Scene. Or connect a Camera to Camera, select the Card in the Node Graph and press Use Selected Card.
3. Check the viewer: the card's outline is drawn with a square on corner 1 (bottom-left) and crosses on the others. Status names the Card and camera it is reading.
4. In Make Nodes, set Frame Range.
5. For a Tracker, press Copy Tracker, click in the Node Graph and press Ctrl+V.
6. For a CornerPin, choose the CornerPin mode, set Reference Frame for Match-move or Stabilise, press Copy CornerPin, select the node to pin and press Ctrl+V.

The panel

The node's panel as Nuke shows it, with the values of a new node. Click any control to see what it does; tabs and sections work as in Nuke.

All controls

Tips

• Unpin Card flattens the card's area of the plate into the texture's frame: paint or patch on it, then a Pin Onto Card CornerPin puts the result back on the surface.
• Pin Onto Card expects an image the size of the card's texture, so the insert lands exactly where the ScanlineRender would draw it.
• Turn on Add Centre Track for a fifth track at the card's centre, useful for 2D elements that only need a position.
• The tracks are named after the Card and the corner (BL, BR, TR, TL), in the order CornerPin uses.
• Pasting while a node is selected inserts the new node below it, as any Nuke paste does: that is how Copy CornerPin lands on the node you want to pin.

Good to know

• On frames where a corner is behind the camera, the Tracker's key for that corner is switched off and the CornerPin has no key. Status counts those frames.
• Only the classic Card node is read, not the newer 3D system's cards. A Card's own deformation (its control points) is ignored: the corners are those of the flat card.
• The camera input accepts Camera nodes only.
• The pasted nodes are baked and not linked back: change the Card or camera, then copy again.

Works with

ANR Point To TrackTurns 3D nodes seen through a camera into 2D tracks: one Tracker, with one track per Axis, Light, Card or other 3D node.ANR Transform ConvertCollapses a chain of CornerPins and Transforms into one CornerPin, Tracker or Transform keyed on every frame, or its inverse.ANR Camera BakeFlattens a camera with parents, expressions or links, or any 3D node, into a plain Camera or Axis keyed on every frame.ANR Track To Locked CameraPuts a 2D track into 3D without a camera solve: a camera that never moves, a card that moves with the track, and an Axis on the tracked point.