As a step up from the previous Mandelbrot Set explorer, I’m running a Terapixel image experience for DWScript Christmas 2013.
This is again on the Mandelbrot set, and involves a massive step up in complexity from the previous version, this one isn’t just server-side computed, it’s “Grid Computed” For the impatient, jump to the browser, or the contribute CPU time page.
The current goal is to reach Level 12 and reach the Terapixel barrier! What is level 12? The image is made of 256×256 tiles, each point in a tile stores the iteration depth in the Mandelbrot Set.
At level 0, there is only one tile (the one you see to the right), which is then subdivided at each level.
At level 1, there are 2^1 x 2^1 = 4 tiles of 256×256.
At level 2, there are 2^2 x 2^2 = 16 tiles of 256×256.
At level 12, there are 2^12 x 2^12 = 4096 x 4096 = 16777216 tiles of 256×256, or 1 Terapixel.
Server-side the data is compressed and won’t take a terabytes of storage, but Level 12 is still anticipated to end up at 10 to 11 Gigabytes.
Why the Mandelbrot Set
The Mandelbrot Set is a fractal, but it’s a very varied one. It is only self-similar and never repeats itself. There only one symmetry, along the Y axis.
The Mandelbrot Set reveals itself more the more computing power you throw at it, in two ways:
- the fractal is revealed as part of an iteration series, the more iterations you allow, the finer the details revealed
- more precision allows to go deeper, double-precision is a minimal, this is why many GPU-based implementations don’t look so good on regular hardware when you zoom (or aren’t so fast)
For instance the previous experiment (on the left) was doing 384 iterations, the new one (on the right) goes up to 65535:
The images come from a zoom level of 11 in the “valley” between the large cardioid and the main bulb. The right image is about 170 times more expensive to compute, so even when computed server-side on fast CPUs, it can’t be computed interactively anymore.