mandlebrot fractal shader

Here an example of the code for a mandlebrot fractal noise written for renderman. In this particular simple shader, you can change the color of the fractal using a spline color. I use 3delight to test the shader inside maya.


surface Mandelbrot(color c1=(1,0,0);color c2=(0,0,1);color c3=(0,0,0))
{
    float u = s;
    float v = t;
    
    //Z^2 + C
    float Zx = 0;
    float Zy = 0;
    float Cx = u;
    float Cy = v;
    
    float i;
    for(i=0;i<100;i=i+1)
    {
        float a = Zx*Zx-Zy*Zy;
        float b = 2*Zx*Zy;
        Zx = a;
        Zy = b;
        Zx = Zx+Cx;
        Zy = Zy+Cy;
        if (Zx*Zx+Zy*Zy>4)
            break;
    
        
    }
    float value = i/100;
    Ci = spline(value,c1,c1,c2,c3,c3)*diffuse(normalize(N));
    Oi = Os;
}