Sergey Sharybin
b9be47e91c
From the math point of view there're two cases: - Clearing the keyframe between two other ones. In this case tracker will first track plane from left keyframe to right one without doing any kind of blending. This will make plane stick to the actual plane motion, but lead to possible jump at the right keyframe. Second step is to track from the right keyframe to the left one with blending. This gives nice transition at the point of second keyframe and this mimics situation when you've been setting keyframes from left to right. - Clearing left-most/right-most keyframe. In this case it's enough to only re-track the plane without blending from the neighbor keyframe without blending.