Raycast原点或Object交点

Question

以下screenToWorld（）方法返回Ray原点（或）对象的交点。如果它是对象的交叉点，如何识别特定对象上的点击事件？

public PointF hitTest(MotionEvent e) {
    return screenToWorld(modelViewMatrix, modelViewProjectionMatrix, e.getX(), e.getY());
  }

  public static PointF screenToWorld(float[] viewMatrix,
                                     float[] projMatrix, float screenX, float screenY) {
    float[] nearPos = unProject(viewMatrix, projMatrix, screenX, screenY, 0);
    float[] farPos = unProject(viewMatrix, projMatrix, screenX, screenY, 1);

    Log.d(LOGTAG,"nearPos ->"+nearPos.length+" "+nearPos);
    Log.d(LOGTAG,"farPos ->"+farPos.length+" "+farPos);

    // The click occurred in somewhere on the line between the two points
    // nearPos and farPos. We want to find
    // where that line intersects the plane at z=0
    float distance = nearPos[2] / (nearPos[2] - farPos[2]); // Distance between nearPos and z=0
    float x = nearPos[0] + (farPos[0] - nearPos[0]) * distance;
    float y = nearPos[1] + (farPos[1] - nearPos[0]) * distance;
    return new PointF(x, y);
  }

  private static float[] unProject(float[] viewMatrix,
                                   float[] projMatrix, float screenX, float screenY, float depth) {
    float[] position = {0, 0, 0, 0};
    int[] viewPort = {0, 0, 1, 1};
    GLU.gluUnProject(screenX, screenY, depth, viewMatrix, 0, projMatrix, 0,
            viewPort, 0, position, 0);
    position[0] /= position[3];
    position[1] /= position[3];
    position[2] /= position[3];
    position[3] = 1;
    return position;
  }