09.01.2024 – Matchmove
Week 11 – Matchmove in Nuke
There are several steps to matchmove the scene:
- Prepare the Original Plate:
- Begin by denoising the original plate to simplify scene analysis.
- Enhance visibility by brightening and sharpening the scene.
- CameraTracker Node:
- Use the CameraTracker node to analyze the scene, excluding problematic areas like reflections using the Roto node.
- In the CameraTracker tab, set source type and mask type. If you lack Lens Distortion and Focal Length information, stick to default settings.
- In the Settings tab, enable ‘Preview Features’ to check trackers.
- Press ‘Track’ and ‘Solve’ after configuring all settings.
- Error Assessment:
- Evaluate the success of your track by checking the ‘Error’ figure. A value under 1 or around 2 indicates a successful track, while values over 4–5 require reconsideration.
- Enhance results by replacing the error-max graph in the ‘AutoTracks’ tab.
- Exporting the Scene:
- Export using ‘Scene’ or ‘Scene+’ and ensure ‘Link Output’ is enabled.
- Scene Alignment:
- Select trackers, right-click, and set the ground plane with ‘Set to selected’.
- In the 3D view, a square of grid represents one centimeter.
- Add scale distance in the Scene tab by measuring the distance using the grid and inputting the figure into the distance knob.
- Creating 3D Objects:
- Select trackers, create 3D objects, and move/rotate them to match the 3D view. Verify matchmove accuracy by creating a card and connecting a grid node for its texture or using a wireframe shader.
- Considerations:
- Matchmove precision is vital across foreground, midground, and background elements.
- Challenges may arise in shots with motion blur, lens flare, and excessive grain.
PointCloudGenerator Node (NukeX only):
- Generate geometry from points using this node.
- Connect source and camera, analyze the sequence, track points, delete rejected points, and change to ‘select vertices.’
- Utilize the Groups tab to create groups with selected vertices and click ‘Bake selected groups to mesh’.
- If you need it to utilize in Maya, you can export data using the WriteGeo node.
Matchmove is crucial in the world of CG, ensuring accuracy across various elements in your scenes. As you progress, challenges like motion blur and lens flare may arise, but employing the right nodes and techniques will lead to successful outcomes.