Thursday April 9 Finish Matchmove and Composite

There will not be a class meeting Thursday – complete this in lieu of the lecture.

Review this video for details on finishing the matchmove and composite:

• Previous “Grace” Matchmove and Comp Example

Upload your checkpoint for P2 to Canvas by the end of Thursday – zip or tgz with one playblast or better of match and set alignment or better and a pdf if any comments or questions. Go through this post and finalize your matchmove, render, and composite to finish assignment and upload final by Tuesday.

Tips

1. If using CameraTracker (beta) instead of (legacy) in Nuke, after the solve make sure to have “Use Beta” unchecked before creating “Scene +” from the dropdown.

2. It is a good idea to generate an undistorted image sequence using the known or solved distortion, and use that as the image plane for the matchmove camera in Maya.

3. Create a WriteGeo node and connect it to the Scene.
   • This will not work if the Scene+ was created with the beta workflow.

4. Use WriteGeo to export an FBX file to import into Maya.

5. In Maya, immediately group the camera and locators together into one new group (Ctrl + G or from the menu) so their transforms relative to each other are preserved.
   • You may want to reduce locator display size so they are smaller and less distracting.
   • After grouping, the entire group can be scaled, rotated, or translated for better alignment with Maya’s grid without breaking the solve.
6. Find the matchmove camera in that group and attach the undistorted image sequence from the original shot to its image plane so that it can be viewed through that camera and also seen in Maya from other cameras if needed.
   • The frame range must match.
   • If needed, generate the image sequence in FFmpeg or Resolve and renumber with a Python or Bash script.

7. Start aligning the set. One good way to begin is to create a proxy box or plane and move that geometry’s pivot point to a corner that you want to align with something in your scene.

8. Choose a known locator from the solve group and snap your proxy box/plane to that point.
   • A point constraint in the correct order can do this, then be deleted.
   • I showed an example using a window corner in Zucker.
   • This could also be a distinct point on a corner, floor, wall, etc.
9. Once snapped, the proxy box/plane can be rotated and potentially scaled (leave translation alone) relative to that pivot point around the known location.
   • This reduces degrees of freedom while scrubbing the timeline and checking the view through the matchmove camera against the image sequence to get the correct orientation and scale.

10. Once at least a proxy plane is in place and does not slip, repeat the process for additional proxy geometry as needed.

11. Light using either the light probe or a manual lighting setup.

12. Render.
    • See the video for more tips on RenderMan AOVs for shadows and reflections.
    • This is also useful: Renderman reflection and shadow holdout example.
13. Bring the renders back into Nuke, then grade and merge as needed using the usual workflow (also see the video) over the undistorted footage, then either:
    • redistort the comp, or
    • distort the renders and merge over the original plate.
14. Again, see the video for more detail.