billboard using ofNode / ofCamera

gistfile1.cpp

//--------------------------------------------------------------
void testApp::draw(){

    glEnable(GL_DEPTH_TEST);
    ofEnableLighting();
    ofLight light;
    light.setPosition(ofPoint(-200,0, -1000));
    light.lookAt( ofPoint(-1000,0,0));
    light.setDirectional();
    light.enable();
    
    cam.begin();

    ofDrawAxis(100);
    
    ofSeedRandom(0);    // always pick the same random positions
    
    for (int i = 0; i < 50; i++){
        
        ofPoint pos(ofRandom(-200,200), ofRandom(-200,200), ofRandom(-200,200));
        
        ofNode posNode;
        posNode.setGlobalPosition(pos);
        posNode.lookAt(cam.getGlobalPosition(), cam.getUpDir());
        ofQuaternion posQuat = posNode.getGlobalOrientation();

        float ang = 0;
        ofPoint vec;
        posQuat.getRotate(ang, vec);
        
        ofPushMatrix();
            ofTranslate(pos);
            ofRotate(ang, vec.x, vec.y, vec.z);
            ofRotate(30,  1,1,0);       // rotate alittle bit, so you can see the "box" of the object
            ofDrawBox(0,0,0,50);
        ofPopMatrix();
    }
    
    cam.end();
    
    
}

in the .h file:

ofEasyCam cam;