Animation Motion Study Generator

Generate an editable flipbook to compare animation easing curves.

Try an example: Twelve drawings with slow-in, slow-out spacing

How it works

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.

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.

Sources

Pencil2D manual: timeline, drawings and onion skin workflow (Pencil2D)

For scripts and AI agents

JSON API: POST https://fliplinemotionstudy.usefulweb.site/api/v1/calculate (same calculation as this page)
Interface description: OpenAPI 3.1 · AI guide: llms.txt
MCP server (Streamable HTTP): https://fliplinemotionstudy.usefulweb.site/mcp · tool name flipline_motion_study

Example request

curl -s -X POST https://fliplinemotionstudy.usefulweb.site/api/v1/calculate \
  -H 'content-type: application/json' \
  -d '{"count":12,"fps":12,"ease":"ease-in-out","fromX":15,"fromY":50,"toX":85,"toY":50}'