To align two shots and store the results as keyframed parameters, do the following:
| 1. | Find two shots that are of the same scene, but have slightly different camera motion and foreground objects. Select Image > Read to load both these shots. |
| 2. | Select Furnace > F_Align. Connect the shot you want to reposition to the source (Src) input of F_Align and the shot you want to match to the reference (Ref) input. View the output from F_Align. |
The source will be immediately repositioned so that it aligns to the reference shot without any need for analysis.
You will see the following banner in the overlay:
No valid key framed analysis found. Analyzing during render.
| 3. | Depending on the exact difference between the two shots, you may need to enable the Scale and/or the Perspective toggles to get a decent alignment. |
| 4. | You may also need to reposition the Analysis Region depending on the differences in foreground detail. However, leaving it at the default position works well for most shots. |
| 5. | Click on the Analyse button. |
F_Align will now start analyzing each frame in the shot, figuring out the four-corner pin and writing it as key frames to the corner pin parameters, Bottom Left, Bottom Right, Top Left, and Top Right. You will find these parameters under Advanced > Four Corner Pin.
F_Align will update the timeline at each frame, and you will see the aligned image render in the output. If you don’t want this to happen, uncheck Render During Analysis.
If you interrupt the analysis, the pins it has keyed until that point will be retained.
| 6. | Play or scrub through the aligned frames. The rendering will be faster as F_Align will no longer need to analyze on the fly. However, if you scrub to a frame where a corner pin has not been keyed, F_Align will re-analyze that frame on the fly. |
| 7. | To see how closely the two clips have aligned, press M on the Node Graph to insert a Merge node. Connect the Merge node’s A input to F_Align and the B input to the reference image. View the output from the Merge node. Then, adjust the mix slider in the Merge controls to dissolve between F_Align’s output and the reference clip you wanted to match. |