Memos From the Cube

Java really isn’t suited to 3D, or anything graphical at all for that matter.

However, as an “academic exercise” (read: product of boredom) I’ve been playing around with making a basic 3D renderer in Java. Thank’s to my friend Alan, I’ve been able to extrapolate on his 3D point mathematics teachings and turn it into a working basic renderer.

Currently I’ve implemented double buffering to eliminate flickering, backface elimination and Z-ordering, and with all the overloading I’ve written I’ve now got a pretty neat 3D library. I’m yet to write any shading code (hence the reason why the below screenshot is ugly – I’ve had to randomly color each face to make the object visible) but I can load in objects from a basic proprietary 3D shape format of Alan’s creation and render them in 3D space. I’ve also added functions for moving/rotating points and objects, which allows the current demonstration code to display several spinning objects.

My shape class can show objects as either solid rendering (pictured), wireframe, or as a point “cloud”.

All great fun, but the performance is pretty horrible. Once more than about 7,000 faces are loaded in, the framerate slows to only a handful of frames per second – a high-quality Torus Knot of 12,000 faces only manages 3 frames per second.

The Z-Sorting for both objects and faces was originally a basic Bubble-sort of my own writing, but for performance reasons I swapped it out with a more efficient (if more complex) Merge sort algorithm. I had to “borrow” the latter from a tutorial site on the Internet — after two complete attempts of my own I gave up and left the sorting code to the experts.

I’ll try to get some more screenshots up in the next few days, and/or coax the applet into running in a webbrowser for a live demonstration.