Camera Tracking - Nuke 101: Professional Compositing and Visual Effects - page 438

Creating the reflective surface
You need a flat surface to reflect on. A flat surface is sufficient to mimic the front glass
on the picture frame. You will use a Card node for that. A Card node is a flat surface 3D
piece of geometry. One way to create such a surface is to create a Card and then manually
position it where the frame is located according to the point cloud. However, there is a
simpler way:
1. Clear the Properties Bin.
2. Double-click CameraTracker1 to open its Properties panel in the Properties Bin.
3. Press the 1 key to view CameraTracker1 in the Viewer.
4. Select all the points inside the picture frame—except for the orange points or
points on the frame itself or outside of it. You can do this by marqueeing them or
Shift-clicking them ( FIGURE 10.31 ) .
Figure 10.31. Selecting all the points in the picture frame turns the points
yellow.