Motion Path Calculator

Yes. Across the calculator's full 0-5000px Arc Height range, arc length only ever increases or stays flat as you raise the height — it never comes back down. The parabolic approximation treats the arc as two straight legs from each endpoint up to the peak, and both legs necessarily lengthen as the peak moves farther from the straight line, whatever your Start and End coordinates are set to.

Direction Angle is the straight bearing from the start point to the end point, measured with atan2, so it always responds to End Y — but which way it moves depends on whether End X sits to the right or left of Start X. When End X is greater than or equal to Start X, raising End Y turns the bearing upward and the angle rises. When End X is less than Start X (a right-to-left path, just as legitimate an input as left-to-right), the relationship mirrors and raising End Y instead turns the angle downward. It is not derived from the curved arc itself, only the two endpoints.

It divides the computed Arc Length by a fixed 24 frames, which is only correct if your motion is meant to complete in exactly one second at 24 frames per second. A different clip duration, a different frame rate, or any eased (non-linear) motion curve will make the real per-frame travel distance vary rather than sit at this one constant figure, so treat it as a rough reference speed rather than a per-frame keyframe value.

No — it only models a single symmetric arc bowed above the straight line between two endpoints, approximated as two straight legs meeting at the peak. A real Bezier curve with independent control-point handles, an S-curve, or a multi-point spline has a shape this two-point parabolic model cannot capture, so treat the Arc Length here as an estimate for a simple bow, not an exact match for handle-based easing tools.