- 2D tracking in Nuke refers to the process of analyzing and following the motion of objects within a two-dimensional space in a video or image sequence. This tracking is essential for tasks such as adding elements to a scene, stabilizing footage, or applying visual effects that need to move with a specific object.
2D Tracking Process
1. Import Footage:
- Open Nuke and import your footage or image sequence.
- Analise the footage on how to approach the shot.
2. Create a Tracker Node:
- In the Node Graph, right-click and select “Tracker” from the menu.
- Connect the Tracker node to your footage.
3. Select Tracking Points:
- Open the Tracker node properties.
- Click “Add Track” to define tracking points on the phone screen.
- Choose high-contrast points that will allow for accurate tracking.
4. Define Tracking Region:
- For each tracking point, draw a tracking region around it.
- These regions should cover the area of the phone screen.
5. Analyze Motion:
- Click “Analyze” in the Tracker node properties.
- Nuke will analyze the motion of the tracking points throughout the sequence.
6. Green De-Spill:
- Use green de-spill to remove the green spill or color contamination that often occurs on edges of the subject when working with green screens.
7. Create a CornerPin Node:
- Add a CornerPin node to the Node Graph.
- Connect the output of the Tracker node to the input of the CornerPin node.
8. Apply Tracking Data to CornerPin:
- Connect the tracking data to the CornerPin’s input parameters.
- This will allow the CornerPin to stabilize the footage based on the tracked motion.
9. Create a Roto Node for the Phone Screen:
- Add a Roto node and draw a shape around the phone screen.
- Animate the shape to account for any movement or rotation that the tracker might have missed.
10. Merge the Replacement Image:
- Import the replacement image for the phone screen.
- Use a Copy or Transform node to size and position it appropriately.
11. Apply CornerPin to Replacement Image:
- Connect the output of the CornerPin node to the replacement image’s input.
- This ensures that the replacement image follows the stabilized motion.
12. Adjust Placement:
- Fine-tune the placement of the replacement image to match the stabilized phone screen.
13. Review and Iterate:
- Scrub through the timeline to review the stabilized phone screen replacement.
- Make manual adjustments as needed for a seamless integration.
14. Negate stablization
- Remove the stabilization with the same tracking data but this time using (Match-move 1-pt) transform
15. Finalize and Render:
- Once satisfied, render the final composition.