3d - Java - Rotating points on a circle -

have been playing around basic 3d. i'm trying keep math relatively simple i'm in year 9.

background info: have 3 int[] variables called xpoints, ypoints , zpoints. thinking putting them in 1 list called nodes decided it's easier not to.

the first forumla tried was:

xpoints[i] = (int) (r*math.cos(math.toradians(d))); ypoints[i] = (int) (r*math.sin(math.toradians(d))); 

this worked rotating cube around 1 axis not others. found formula looked promising multiple axis can't work. faces seem shrink during each loop, ending in single point (the centre).

xpoints[i] = (int) (x * cos_t - y * sin_t) ypoints[i] = (int) (y * cos_t + x * sin_t) 

the full function applying math:

public void rotatez(double theta){     theta = math.toradians(theta);     double cos_t = math.cos(theta);     double sin_t = math.sin(theta);     (int = 0; < xpoints.length; i++){         double x = xpoints[i] - x_off;         double y = ypoints[i] - y_off - ypoints_mod[i];         xpoints[i] = (int) (x * cos_t - y * sin_t) + x_off;         ypoints[i] = (int) (y * cos_t + x * sin_t) + y_off + ypoints_mod[i];         system.out.println(x+", "+y);     }    } 

if need anymore info please let me know (wasn't quite sure how word this)

thanks,

amazing work 9 years old boy!! great!! search euler rotation rotating point or vector on 3-axis.