Graphics Reference
In-Depth Information
Take a look at the markers like this. If the reconstructed 3D marker is more accurately placed than the 2D
marker with respect to the feature it's supposed to be tracking, then you can move the 2D marker by hand to be
closer to the 3D marker. Otherwise, you should fix other problems in the tracked scene to get a more accurate
camera solution.
Another place to look for problems is the graph view of the Clip Editor, shown in
Figure 10-21
.
Thisshowsyouthespeedofmotionalongthex-andy-axesofeach2Dmarkerinredandgreen,respectively.
It also shows a blue line that indicates the average solve error. Look for places where this blue line is high or
where the red or green lines seem anomalous or more sudden than usual. These could indicate problems but not
necessarily. If a marker goes from disabled to enabled, the change will show up as a sudden jump upward or
downward, but this doesn't indicate a problem.
Figure 10-21
The Clip Editor graph view
Another thing that can cause problems for a track is lens distortion. Although Blender does refine distortion
parameters (the K1 and K2 values listed in the Refinement menu), it is sometimes helpful to tweak distortion
by hand. You can do this by selecting Distortion mode in the Clip Editor header menu. In Distortion mode you
can display a grid overlay like the one shown in
Figure 10-22
. As you can see, the grid is bulging outward in
the figure, indicating that there is a mismatch in the scene reconstruction and the footage distortion. Adjust the
K1, K2, and K3 parameters to straighten the grid as much as you can and try running the camera solver again.
