KOEN

Gravity Doodle

LAB ยท GRAVITY DOODLE

Draw lines that turn into chains and fall, bounce and tumble under gravity. Add fixed walls, flip gravity in any direction and fling your doodles around, right in your browser.

Draw a line anywhere. Let go and watch it fall!

HOW TO

How to use

  1. Draw any line with the Falling pen. When you let go, it turns into a chain of points that falls, bouncing off the floor and walls.
  2. Lines drawn with Fixed wall stay put, so you can build ramps or baskets. Use Grab to drag and throw lines that have fallen.
  3. Use the direction pad or the arrow keys (click the pad first) to send gravity up, down, left, right or switch it off, and adjust its strength.
  4. Material (Floppy, Bouncy, Rigid) applies to new lines, while Bounciness applies to all lines right away. Tidy up with Undo, Eraser and Clear all.
PAIRS WELL WITH

Pairs well with

FAQ

FAQ

Is this a real physics engine?

It's a lightweight approximation built with Verlet integration and distance constraints. Each line becomes a chain of evenly spaced points that collide with each other, the fixed walls and the edges. Very fast lines or narrow gaps can occasionally let lines pass through each other.

I drew a circle but it squished out of shape.

Choose the Rigid material and draw it again. Extra diagonal links help it keep its shape. If the start and end of your stroke are close together, it closes into a loop. Floppy behaves like a piece of string.

Will it slow down if I draw a lot?

Once falling lines pass 1,800 points, the oldest lines are removed automatically. The simulation rests when everything stops moving and pauses when the tab is hidden or the pad is scrolled out of view.

Can I save my drawing?

There's no option to save the drawing as a file. Only your settings, such as pen color, thickness, material, bounciness and gravity, are saved in this browser.