Computing Motion Vectors

If no motion vectors have been imported, you can compute them inside a composition by adding a Motio node. Certain tool nodes, such as the Retimer, will detect the absence of motion vector inputs, and will trigger the use of its internal Motio engine to automatically compute motion vectors. Computing motion vectors explicitly allow you to use the vectors for more than one vector consumer tool. For example, you may want to retime some footage with different speeds and then quickly compare the results. Instead of computing the vectors twice (in each Retimer), you can use the Motio tool's output twice.

The Motio tool has a non-animated scalar parameter, called Quality, as a well as a Show Vectors parameter—see Show Vectors. This parameter controls the quality of the motion vectors by applying the motion analysis only to lower-resolution versions of the input image, up to the resolution specified by the quality parameter.

To compute motion vectors inside a composition with the Motio tool and compare retimed footage:

1. Drop a Motio tool into the Schematic view of a composition you want to retime.
2. Connect the output of the footage to the input of the Motio node.
3. Add a Retimer tool to your dependency tree, and rename it HalfSpeed.
4. Make the Speed value 0.5.
5. Set the Retimer's context point to C1—see Setting Context Points.
6. Connect the three Motio outputs to the corresponding inputs of the HalfSpeed Retimer.
7. Set the target of a Player to context point C1—see Setting the Target.
8. Add a second Retimer to Schematic and change its name to QuarterSpeed and enter 0.25 into its Speed value editor.
9. Set the Retimer's context point to C2—see Setting Context Points.
10. Connect the three Motio outputs to the corresponding inputs of the QuarterSpeed Retimer.
11. Set the target of a second Player to context point C2—see Setting the Target.
12. Play and compare the two retimed clips.