Print Page - 3D Burning Ship formula and .frag file

Hello. I've written Fragmentarium code for the 3D burning ship. Here's a picture of the main miniship on the western antenna (click for full-size):
(http://2imgs.com/2i/t/5fb1a78d5e.jpg) (http://2imgs.com/5fb1a78d5e)

Here is one of the Julia sets of this formula (this Julia and the others I posted in the gallery are included as presets).
(http://nocache-nocookies.digitalgott.com/gallery/16/8614_18_10_14_11_01_50.jpeg) (http://nocache-nocookies.digitalgott.com/gallery/16/8614_18_10_14_11_01_50.jpeg)

This is essentially the standard mandelbulb with abs() applied to all axes before the power operation. Here's the iteration formula, in trig form (I've written it in pseudocode using only scalar variables, to make it easier to understand for those who don't know glsl).

Code:

x = abs(x)
y = abs(y)
z = abs(z)

r = sqrt(x*x + y*y + z*z)

phi = atan2(y,x)
theta = asin(z/r)

r = pow(r, Power)
theta = theta * Power
phi = phi * Power

x = r*cos(theta)*cos(phi)
y = r*cos(theta)*sin(phi)
z = r*sin(theta)

x+= JuliaX
y += JuliaY 
z += JuliaZ

I made two versions, a fast, power-2 only version, and arbitrary-power version that is much slower as it uses trig functions. The arbitrary power version also allows an arbitrary rotation to be applied each iteration, while the fast version ignores the RotVector and RotAngle parameters. Both versions use 4-point distance estimation, because the fast scalar DE approximation is not accurate for a fractal with this much stretching and skewing (it would probably work ok for the higher powers, but then you'd essentially be looking at the mandelbulb). So it's a bit slow(turn down the detail setting to get it to run faster). Let me know if you get any compiler errors.

I also uploaded a slightly modified version of Syntopia's DE_Raytracer that I used to render the above images. I changed it so that the spot light shadows don't influence the cam light, so now the cam light can act as a proper fill light for the shadowed areas. (NOTE: It will work just fine with the standard raytracer).

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Fractal Software => Fragmentarium => Topic started by: laser blaster on October 22, 2014, 12:27:57 AM