Today we used NukeX for the first time to create proxy geometry, which is used to track an object's movement. This is done so that VFX can be accurately added to footage, and won't distort or be in the wrong position.
We were given footage to use, so we opened NukeX and created a new project. There is an area in NukeX which maps out all the actions that have been taken to edit or change the footage. The first thing we did was un distort the footage. This is done by bringing in another piece of footage of a grid, which will show how bad the distortion is. We then correct it, and use the same method on the actual footage (as these two things will be shot with the same camera).
This is the lens distortion menu. At the top, you can change the type of distortion and the filters and settings that you will 'solve', which can be done in the Analysis section.
The next thing to do is add a camera tracker, which will track the movement of the camera, and add in a scanline renderer. A scanline renderer will track the geometry automatically for you and place vertices on places it will track through the footage. This means we can track certain points of the footage and the movement they have. With the footage we had, nothing moved apart from the camera recording, which means it is easier to track things.
You can press tab over the viewer, and see the 3D geometry that has been created. It will be spread out across a grid, a lot like Maya. They will take on the colours of the points they are at so that they are easier to identify. The next thing to do is to add a cube. This cube is what I will turn into a computer. Using the vertices, I can match up the computer and resize it to be as accurate as possible.
Then all that was left to do was render the undistorted camera plate, which is the footage undistorted, and the wireframe render. This is done by pressing tab and creating a 'write', which will allow you to save the composition. All I had to do was add a .mov to the end to make sure Nuke knew that is was a video file. The same thing is done for the wireframe.
This is all I could do in the lessons, so I will continue through the videos I was following next week. I think I did well at understanding why certain things worked the way they did, and how to link up and create new parts of a composition in the composition map. I could've done better at matching the geometry, however, although the tracking may not be accurate enough to be completely accurate (as it was done automatically).
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