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GreenEminence89 · 2012-07-26 07:55:35

Hello,

I'm having trouble with setting up correct coordinates for little shader taken from GuoQiang Xie Slim template. It's based on Fibonacci sequence, distributing little dots across the surface.

Here's the code:

Code:

float circle(float centerx, centery, radius)
{
float result;
extern float s,t;
float tt = 2*sqrt(pow(centerx-s,2)+pow(centery-t,2));
  
  if( pow(s-centerx,2) + pow(t-centery,2) <= radius *radius)
//    result = 1;
    result =  abs (smoothstep(0,radius*2,tt)-1);
  else
    result = 0;
  
return result;
}
  
  
surface tiaDot(float spread_radius = .05; float seed_num = 80; float dot_radius = .02)
{
float i = 0 ,x = 0, y = 0, r =0;
  
float result = 0;;
  
for(i=0; i<= seed_num; i+=1)
{
    x =  sqrt(i) * spread_radius * cos (radians(i*137.5));
    y =  sqrt(i) * spread_radius * sin (radians(i*137.5));
    result += circle(x+.5, y+.5, dot_radius); 
} 
Ci =  result;
}

Everything looks great attached to simple polygon, but not so great when attached to a sphere.

Any idea how to alter the code to make an even distribution across the sphere? The idea was to make the dots dissapear on bottom and top part of a sphere (just like a strawberry pattern).

Forums

#1 2012-07-26 07:55:35

Fibonacci sequence coordinates

Code:

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