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Hardware Heritage

"Bob" (Blitter Object) is the Amiga term for a sprite drawn into memory. Shadebobs take this further by using additive blending. Each bob adds its color value to the pixels beneath it.

Amiga Blitter

The Blitter had logic channels (A, B, C, D) that could be combined. Shadebobs used a form of saturation arithmetic to add pixel values.

Visuals

When hundreds of bobs overlap, they create intense, glowing, neon-like trails. It was a staple of 90s intros.

Lissajous

The movement path is usually a Lissajous curve—a parametric equation that creates complex, looping knots.

Shadebobs

Additive sprite blending trails.

Modern JS (Canvas)

ctx.globalCompositeOperation = 'lighter';
for (let i = 0; i < 50; i++) {
  let x = Math.sin(t + i) * w;
  let y = Math.cos(t + i) * h;
  ctx.drawImage(bobSprite, x, y);
}