#waves on a #perspectives #sphere -- #d… by f8f82804

function u(t) {

c.width=1920 // clear the canvas
for(i=0;i<9;i++)
x.fillRect(400+i*100+S(t)*300,400,50,200) // draw 50x200 rects

} // 122/140

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    u(t) is called 60 times per second.
    t: Elapsed time in seconds.
    S: Shorthand for Math.sin.
    C: Shorthand for Math.cos.
    T: Shorthand for Math.tan.
    R: Function that generates rgba-strings, usage ex.: R(255, 255, 255, 0.5)
    c: A 1920x1080 canvas.
    x: A 2D context for that canvas.

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f8f82804

remix of d/11689 by u/f8f82804

function u(t) {

for(i=c.width^=0;i--;x.fillRect(X/d+960,Y/d/.9-1150,s=47-d*2e4,s))a=S(ϕ=i/612),θ=i*37+C(i/99+t),d=Math.hypot(X=S(θ)*a,Y=C(ϕ)+3,C(θ)*a+5)/3e3

Jan 11 2019 8:11 PM UTC

}// 140/140

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#waves on a #perspectives #sphere -- #d3 #pointcloud

u/f8f82804

this dweet uses a better perspective transform based on Math.hypot -- #hypot
u/f8f82804

The projection still isn't perfect, because I'm rotating the sphere's axis towards the viewer by positioning it below the camera. The resulting distortion is approximately corrected by scaling the Y coordinate with /.9.
u/f8f82804

#perspective


      u(t) is called 60 times per second.
      t: elapsed time in seconds.
      c: A 1920x1080 canvas.
      x: A 2D context for that canvas.
      S: Math.sin
      C: Math.cos
      T: Math.tan
      R: Generates rgba-strings, ex.: R(255, 255, 255, 0.5)

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