Android上的OpenGl ES對射線採集代碼進行微調

Question

我使用min3d和我在網上發現的一些代碼實現了射線採集，但是當我實現它時，我注意到它的某些時候意味着當我點擊一個盒子時有時出錯一個被挑選。有時候，挑選的人甚至不在屏幕上。這花了相當多的代碼，以在第一時間得到實現，但是主要的兩種方法我稱之爲有以下幾種：

private void rayPicking(float x, float y) 
{ 
    //intersection with 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 we check each model if it was tapped and if several models were tapped, we take only that which is closer to the 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; 
} 

現在我也曾嘗試推行域剔除，但已經做了，它減緩事情一路下滑，因爲我沒有做太多的工作來優化它，它本身並沒有運行。但是如果有人能夠看，並且可以給我一些關於如何使它更準確的指示，那將是非常棒的。在這裏我稱之爲採摘方法。

_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: 
         // we use ray picking only when the tap wasn't longer than 0.5 sec and if we almost didn't move our finger 
         //Log.w("this is touch y"+e.getY()+" viewport is"+scene.getViewport()[3], "this is 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; 

      } 
      } 
     ); 

Answer 1

錯誤你聽起來像你犯了一個錯誤，你碰撞檢測，我有一個功能，我有點產品的錯誤，並導致一些非常奇怪的結果。你能發佈更多的碰撞算法嗎？

我在這裏實現了射線拾取：http://android-raypick.blogspot.ca/我沒有粘貼代碼，因爲它有一個分配，可以隨意比較你的代碼和這段代碼，這段代碼已經過測試和工作。