With so little info I can't really help you much. I'm assuming you're following this old article to achieve what you want. However, it's unclear to me what your goal is.
If your goal is to complete the tutorial for the sake of exercise, then I will need to know a lot more (e.g., where you got stuck and what output you're getting from the processing IDE; what your code looks like at this time, etc); otherwise, most of the examples depicted in that article have already been ported to C/C++ and are available at the gallery for your enjoyment.
"Spark Pixels v4" is in part, the result of that effort - in there you'll find CUBES/CUBE PAINTER/CUBE CLASSICS/SPECTRUM; and in the recently-released "Christmas Pack" you'll find FIREWORKS (an improved version of the one in the factory demo reel, which was based on the Spheres exercise) available to you at a click.
Try flashing "Spark Pixels v4" and afterwards, head to the spark pixels area to discover how you can switch between and fine-tune these visualizations from your browser.
If you follow this avenue, you'll also want to try the cube painter area, to play with drawing sweet graphics to your cube in real time, with no programming.
Let me know what you decided and we'll go from there.