# Animation Motion Study Generator

> Generate an editable flipbook to compare animation easing curves. Create a ball moving between two canvas positions with linear, ease-in, ease-out or smoothstep spacing. Download the project and open it in Flipline to draw over it.

Part of usefulweb.app (https://usefulweb.app/). Results are deterministic calculations from the inputs and the listed assumptions; the API returns exactly what the web page shows.

## Use it
- Human interface: https://fliplinemotionstudy.usefulweb.app/ (interactive tool at https://fliplinemotionstudy.usefulweb.app/tool)
- JSON API: POST https://fliplinemotionstudy.usefulweb.app/api/v1/calculate with a JSON object of inputs (schema: https://fliplinemotionstudy.usefulweb.app/api/v1/tool)
- OpenAPI: https://fliplinemotionstudy.usefulweb.app/openapi.json
- MCP (Streamable HTTP): https://fliplinemotionstudy.usefulweb.app/mcp - tool `flipline_motion_study`

## Inputs
- count (integer): Drawing count
- fps (integer): Frame rate (FPS)
- ease (select): Spacing curve
- fromX (number): Start X (%)
- fromY (number): Start Y (%)
- toX (number): End X (%)
- toY (number): End Y (%)

## Method
- Progress samples include both endpoints: t = index / (drawing count − 1).
- Easing: linear t, ease-in t², ease-out 1 − (1 − t)², smoothstep t²(3 − 2t). Canvas positions are percentages.
- This generates a deterministic circle-motion project, not automatic inbetweening of arbitrary artwork. Each drawing is editable.