C++ IntersectAction::getHitPoint方法代码示例

void key( unsigned char key, int , int )
{
    switch ( key )
    {
    case 27:    exit(0);
    }
    
    // Intersect
    
    IntersectAction * act = IntersectAction::create();
    
    static Pnt3f pnts[] = { Pnt3f( 0,0,1 ), Pnt3f( 1,0,1),  Pnt3f( 2,0,1), 
                Pnt3f( 3,0,1), Pnt3f( 0,0,1 ), Pnt3f( 0,0,1 ), 
                Pnt3f( 0,0,1 ),Pnt3f( 0,0,1 ), Pnt3f( 0.9,0.9,1 ), 
                Pnt3f(-Inf,-Inf,-Inf) };
    static Vec3f dirs[] = { Vec3f( 0,0,-1), Vec3f( 0,0,-1), Vec3f( 0,0,-1),  
                Vec3f( 0,0,-1), Vec3f( 0,-.2,-1), Vec3f( 0,.2,-1),  
                Vec3f( -.2,-.2,-1), Vec3f( .2,.2,-1), Vec3f( 0,0,-1 ),
                Vec3f(-Inf,-Inf,-Inf) };
    
    static int i = 0;

    act->setLine( Line( pnts[i], dirs[i]) );

    act->apply( iroot );

    std::cerr << "Line " << act->getLine().getPosition() << " dir " 
         << act->getLine().getDirection() << " hit: " << act->didHit() << " ";

    beginEditCP(points);
    points->setValue( pnts[i],                           0 );
    points->setValue( pnts[i] + (dirs[i] * Real32(3.0)), 1 );

    if ( act->didHit() )
    {
        std::cerr << " object " << act->getHitObject() 
             << " tri " << act->getHitTriangle() 
             << " at " << act->getHitPoint();

        TriangleIterator it( act->getHitObject() );
        it.seek( act->getHitTriangle() );
        
        Matrix m;
        act->getHitObject()->getToWorld(m);

        Pnt3f p = it.getPosition(0);
        m.mult(p, p);
        points->setValue( p, 2 );
        p = it.getPosition(1);
        m.mult(p, p);
        points->setValue( p, 3 );
        p = it.getPosition(2);
        m.mult(p, p);
        points->setValue( p, 4 );
    }
    else
    {
        points->setValue( Pnt3f(0,0,0), 2 );
        points->setValue( Pnt3f(0,0,0), 3 );
        points->setValue( Pnt3f(0,0,0), 4 );
    }
    endEditCP(points);

    std::cerr << std::endl;

    glutPostRedisplay();
    
    if ( pnts[++i][0] == -Inf )
        i = 0;
}

// react to keys
void keyboard(unsigned char k, int x, int y)
{
    switch(k)
    {
        case 27:    
        {
            OSG::osgExit();
            exit(0);
        }
        break;

        case ' ':   // send a ray through the clicked pixel
                /*
                    Intersection testing for rays is done using an
                    IntersectAction. The ray itself is calculated by the
                    SimpleSceneManager, given the clicked pixel.
                    
                    It needs to be set up with the line that is to be
                    intersected. A line is a semi-infinite ray which has a
                    starting point and a direction, and extends in the
                    direction to infinity.
                    
                    To do the actual test the Action's apply() method is used.
                    
                    The results can be received from the Action. The main
                    difference is if something was hit or not, which is
                    returned in didHit().
                    
                    If an intersection did occur, the other data elements are
                    valid, otherwise they are undefined.
                    
                    The information that is stored in the action is the object
                    which was hit, the triangle of the object that was hit (in
                    the form of its index) and the actual hit position.             
                */
                {
                Line l;
                
                l = mgr->calcViewRay(x, y);

                std::cerr << "From "  << l.getPosition () 
                          << ", dir " << l.getDirection() << std::endl;
    
                IntersectAction *act = IntersectAction::create();
                
                act->setLine(l);
                act->apply(fileroot);
            
                beginEditCP(isectPoints);
                isectPoints->setValue(l.getPosition(), 0);
                isectPoints->setValue(l.getPosition() + l.getDirection(), 1);
            
                // did we hit something?
                if (act->didHit())
                {
                    // yes!! print and highlight it
                    std::cerr << " object " << act->getHitObject  () 
                              << " tri "    << act->getHitTriangle() 
                              << " at "     << act->getHitPoint   ();
                    
                    mgr->setHighlight(act->getHitObject());
                    
                    // stop the ray on the hit surface
                    Pnt3f is = l.getPosition() + 
                                l.getDirection() * act->getHitT();
                                
                    isectPoints->setValue(is, 1);
                    
                    // find the triangle that was hit
                    TriangleIterator it(act->getHitObject());
                    it.seek(act->getHitTriangle());

                    // Draw its normal at the intersection point
                    isectPoints->setValue(is, 2);
                    isectPoints->setValue(is + act->getHitNormal() * 5, 3);

                    
                    // calculate its vertex positions in world space
                    Matrix m;
                    act->getHitObject()->getToWorld(m);
            
                    // and turn them into a triangle
                    Pnt3f p = it.getPosition(0);
                    m.mult(p, p);
                    isectPoints->setValue(p, 4);
                    p = it.getPosition(1);
                    m.mult(p, p);
                    isectPoints->setValue(p, 5);
                    p = it.getPosition(2);
                    m.mult(p, p);
                    isectPoints->setValue(p, 6);
                }
                else
                {
                    // no, get rid of the triangle and highlight.
                    isectPoints->setValue(Pnt3f(0,0,0), 2);
                    isectPoints->setValue(Pnt3f(0,0,0), 3);
                    isectPoints->setValue(Pnt3f(0,0,0), 4);
                    
//.........这里部分代码省略.........