Quote:
Originally Posted by -Vit-
when you reverse or lengthen the vectors you need to ensure they don't point outside the frame.
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Actually, that's exactly the case that interests me. If the *full length* vector points outside the frame, that doesn't mean the vector isn't useful, as you may only want to interpolate to a point in time, say, 50% of the way between frame N and frame N+1, based on previous motion in frames N-1 and N. The case that interests me especially at the moment is rate-doubling a scene where a person falls out of shot between two frames. With current MVtools methods, the frame created in between the last appearance of the falling body and the first frame where it's absent has a kind of shrivelled, distorted & faded version of the falling body left in the place where it was last seen. Now, some distortion of the body probably can't be avoided; but what matters is that it should *not* appear frozen space, but continue to fall along its original trajectory.
I'd suggest that you allow switching between two or more strategies for "beyond the frame" vectors, e.g.:
1. Zero them, and give them zero confidence ratings (the "no tolerance" option! )
2. Truncate them to the edge of the frame, and give them low confidence ratings (the "right direction, wrong speed" option);
3. Let them point to where they naturally would (i.e. don't modify them because of the frame boundary), and calculate confidence ratings as you would for any other vector (the "this is the truth, whether you can handle it or not" option.
).
The idea with option 2 is to avoid any problems if whatever filter the vectors are passed on to (e.g., MFlowInterp or MCompensate) can't cope with any vector that points beyond the frame: You can still at least indicate that the object/block keeps moving in that general direction, even if the rate of movement is reduced.
Option 3 will only be useful if the following filter will accept vectors regardless of where they point, and then handle them appropriately... Which I *hope* MFlowInterp does, or at least can be made to with a slight modification.