java - OpenGl ES on android fine tuning of ray picking code -

ive implemented ray picking using min3d , code found online when implemented notice off bit times meaning when click on 1 box wrong 1 picked. 1 picked isnt on screen. took quite bit of code implemented in first place main 2 methods call following:

private void raypicking(float x, float y) {     //intersection near plane     float[] near = new float[4];     glu.gluunproject(x, scene.getviewport()[3] - y, 0f, scene.getgrabber().mmodelview, 0, scene.getgrabber().mprojection, 0, scene.getviewport(), 0, near, 0);     if (near[3] != 0)     {         near[0] = near[0] / near[3];         near[1] = near[1] / near[3];         near[2] = near[2] / near[3];     }     number3d near3 = new number3d(near[0], near[1], near[2]);      //and far plane     float[] far = new float[4];     glu.gluunproject(x, scene.getviewport()[3] - y, 1f, scene.getgrabber().mmodelview, 0, scene.getgrabber().mprojection, 0, scene.getviewport(), 0, far, 0);     if (far[3] != 0)     {         far[0] = far[0] / far[3];         far[1] = far[1] / far[3];         far[2] = far[2] / far[3];     }     number3d far3 = new number3d(far[0], far[1], far[2]);      box firstpicked = null;     box currentmodel = null;     number3d currentcoords = null;     number3d firstpickedcoords = new number3d();  if (!sceneboxes.isempty()) {     //here check each model if tapped , if several models tapped, take closer near clipping plane     iterator<box> itr = sceneboxes.iterator();     while (itr.hasnext())     {         currentmodel = itr.next();         currentcoords = new number3d(currentmodel.position().x, currentmodel.position().y, currentmodel.position().z);         if (picked (far3, near3, currentcoords, 1.2f))              if (firstpicked==null)                  {                     firstpicked = currentmodel;                     firstpickedcoords.setallfrom(currentcoords);                  }             else if (number3d.add(currentcoords, near3).length() < number3d.add(firstpickedcoords, near3).length())                  {                     firstpicked = currentmodel;                     firstpickedcoords.setallfrom(currentcoords);                 }     } }         if (firstpicked != null) // if model picked      {         string temp = firstpicked.gettitle();         string temp2 = firstpicked.getlink();         log.w("3d touch working "+temp, "3d touch working "+temp);         intent intent = new intent(curact.this, webviewer.class);         intent.putextra("clkurl", temp2);         intent.putextra("clkuid", curr_uid);         intent.putextra("rid", curr_rid);         startactivity(intent);          firstpicked = null;         temp = null;         temp2 = null;      } }  private boolean picked(number3d a, number3d b, number3d q, float r) {     float ab = (float) math.sqrt((a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y)+(a.z-b.z)*(a.z-b.z));     float aq = (float) math.sqrt((a.x-q.x)*(a.x-q.x)+(a.y-q.y)*(a.y-q.y)+(a.z-q.z)*(a.z-q.z));     float bq = (float) math.sqrt((b.x-q.x)*(b.x-q.x)+(b.y-q.y)*(b.y-q.y)+(b.z-q.z)*(b.z-q.z));      float p = (ab + aq + bq) / 2;      float hh = (float) math.sqrt(p * (p - ab) * (p - aq) * (p - bq));     float h;     if (ab!=0) h = 2 * hh / ab; else h = 2*hh;      if (aq<h) h = aq;     if (bq<h) h = bq;      if (h<r)return true; else return false; } 

now have tried implementing frustum culling having done slows things way down because didnt optimize , not running natively. if 1 can , maybe give me pointers on how make more accurate awesome. heres call picking methods.

 _glsurfaceview.setontouchlistener(          new view.ontouchlistener() {              @override             public boolean ontouch(view arg0, motionevent e) {                  switch (e.getaction() & motionevent.action_mask)                  {                     case motionevent.action_down:                         startx = e.getx();                         starty = e.gety();                         trace = 0.0f;                         time = system.currenttimemillis();                         touchmode = drag;                     break;                      case motionevent.action_up:                         // use ray picking when tap wasn't longer 0.5 sec , if didn't move our finger                         //log.w("this touch y"+e.gety()+" viewport is"+scene.getviewport()[3], "this touch x"+e.getx());                         if ((system.currenttimemillis()-time < 500) && (trace<scene.getviewport()[3]*0.075)) raypicking(e.getx(), e.gety());                         time = 0;                      case motionevent.action_pointer_up:                         touchmode = none;                     break;                 }                 return true;              }             }         ); 

the bug have sounds making mistake in collision detection, had bug in function had dot products , caused odd results. can post more of collision algorithm?

i implemented ray picking here: http://android-raypick.blogspot.ca/ did not paste code here because there allot of it, feel free compare code code, code tested , working.