Black Hole 黑洞漩涡
Two hundred particles whose radius shrinks by 1% per frame while their angle keeps advancing. 两百个粒子，半径每帧缩 1%，角度持续前进。
Runs live on this page. Move the pointer, click, or drag — whichever the effect listens for. 就在本页实时运行。移动鼠标、点击或拖拽——看它响应哪一种。
How it works原理拆解
r *= 0.99 is a geometric decay, so a particle covers the same *proportion* of remaining distance each frame — that is what makes the infall accelerate visually without an explicit force. Brightness is tied to radius (Math.min(80, p.r)), so particles glow brighter as they get closer, then respawn at r=250. r *= 0.99 是几何衰减，意味着每帧吞掉的是「剩余距离的固定比例」——不用写任何力，下落感自己就加速了。亮度绑定在半径上（Math.min(80, p.r)），越靠近中心越亮，缩到 4 就在 r=250 处重生。
What to change可以改的地方
- 1Use r *= 0.97 for an aggressive, violent collapse.
- 2Randomise the decay per particle so the stream looks ragged instead of uniform.
- 1改成 r *= 0.97，会变成暴烈的塌缩。
- 2每个粒子的衰减率做成随机，粒子流就不均匀，看起来更毛躁。
Source code源码
Self-contained — paste it into any HTML file and it runs. No libraries. 完全独立——粘进任意 HTML 文件就能跑，不需要任何库。