Keep a 2D character grounded when animation frames have different bounds
When individual animation frames have different transparent margins, centering each cropped image in the same rectangle can make a character appear to bounce. The pixels are not necessarily wrong: the placement rule is moving the artwork as the bounding box changes. A steadier approach is to pick an anchor that has the same meaning in every frame. For a grounded walk, that might be the point where the supporting foot meets the floor. For a flying character, a point near the torso can be more use
