The "Download Now" link directs you to the iTunes App Store, where you must continue the download process. You must have iTunes installed in order to open the link, and you must have an active iTunes account to download the application. This download may not be available in some countries.
This is the lite version of the Quaternion Julia Raytracer App. The full app adds features such as high quality rendering, full screen rendering and shadows. Just like the traditional Julia fractal, a quaternion Julia fractal is computed as stable complex points of an iterative funtion in the complex space. However, in contrast to 2D julia fractals, 4-dimensional complex numbers, so called quaternions, are used instead of 2-dimensional complex numbers. This App uses the GPU of the iPhone to compute a 3D slice through the 4D complex space of the quaternion Julia set by raytracing with OpenGL ES 2.0 shaders. Instructions: A one finger drag rotates the camera around the object, a two finger pinch zooms and a three finger drag translates the camera. Double/Triple tap and drag the finger horizontally or vertically to change the shape of the quaternion Julia fractal. You can also set these constant in the Settings tab. The Settings tab also allows to enable an environment that is mirrored on the Julia set. The accuracy of the fractal surface can also be set here.