OpenGL and OpenInventor merging problem

[louis <dumais01@xxxxxx>]

Hi,


I`m having technical problems merging OpenGL and Open Inventor and I'm
asking for help to solve the problem. I could give a small paypal gift
to the person solving the “equation”. What I'm trying to do is to use
OpenGL and OpenInventor in the same GL context and using the same camera
for OpenGL and OpenInventor. This camera is the SoCamera from the
OpenInventor package. This mean something like this:


void draw(){

drawTheInventorStuff();

drawTheOpenGLStuff();

}



The problem is that I cant get the same exact visualization coordinates
for OpenGL and OpenInventor with the SoCamera and I dont know why. I
have been reading a lot on the SoCamera and looking at the source code
to finally isolate what I think are the two functions needed for my
task : SbViewVolume::getMatrix() and SbViewVolume::
getMatrices( sbMatrixAffine , sbMatrixProjection) . Basically, at the
moment, what I do is to take the SbViewVolume from the camera and
getMatrix:


SbViewVolume cameraSbViewVolume;

cameraSbViewVolume = camera->getViewVolume();

sbMatrixCamera= cameraSbViewVolume.getMatrix();//working


then I use


glMatrixMode(GL_PROJECTION);

glLoadIdentity (); 

glMultMatrixf(sbMatrixCamera[0]);


before drawing my GL stuff to get the same camera view than in my
OpenInventor rendering pipeline. Its working for the exception of an
annoying perspective problem or Viewport Ratio problem and I dont know
how to solve it. I invite you to take a look at the problem by looking
at a small video you can find at:

http://www.netchilds.com/Louis/test.mpeg


(If everything worked correctly, you could see only one plane and one 6
DOF mechanism but its not the case. You will notice I have the same
problem with perpective and ortho camera.)


If you know how to solve the problem, what matrix or GL call I should be
using please message me todumais01@xxxxxxxxxxxxx . I'm including the
code below I'm using in the video to give you a better idea of my
problem.


Thank you for your help,

Louis-Charles Dumais 


The Drawing loop of the gl windows:




void Fl_Inventor_Window::draw()

{


adjustCameraClippingPlanes();

scenemanager->render();

glDraw();

glFlush();

}


and my glDraw command:


void Fl_Inventor_Window::glDraw(){

glMatrixMode( GL_PROJECTION ); 

glLoadIdentity(); 

SbViewVolume cameraSbViewVolume;

cameraSbViewVolume = camera->getViewVolume();

SbMatrix sbMatrixCamera; 

sbMatrixCamera= cameraSbViewVolume.getMatrix();

glMultMatrixf(sbMatrixCamera[0]);

glEnable(GL_DEPTH_TEST);


//start of dump lightning

GLfloat LightAmbient[]= { 0.75f, 0.75f, 0.75f, 1.0f };

//GLfloat LightAmbient[]= { 1.0f, 1.0f, 1.0f, 1.0f };

GLfloat LightDiffuse1[]= { 0.0f, 1.0f, 0.0f, 1.0f };

GLfloat LightDiffuse2[]= { 1.0f, 0.0f, 0.0f, 1.0f };

GLfloat LightPosition1[]= { 1.0f, 0.0f,0.0f, 1.0f };

GLfloat LightPosition2[]= { -1.0f, 0.0f,0.0f, 1.0f };

//GLfloat LightPosition[]= { -1.0f, 0.0f, 0.0f, 1.0f };

//GLfloat LightPosition1[]= {tempSbVec3fPos[0], tempSbVec3fPos[1],
tempSbVec3fPos[2],1.0f};

//GLfloat LightPosition2[]= {tempSbVec3fPos[0], -tempSbVec3fPos[1],
tempSbVec3fPos[2],1.0f};

glEnable(GL_DEPTH_TEST); // Enables Depth Testing

glDepthFunc(GL_LEQUAL); // The Type Of Depth Testing To Do

glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST); //

glLightfv(GL_LIGHT3, GL_AMBIENT, LightAmbient); 

glLightfv(GL_LIGHT3, GL_DIFFUSE, LightDiffuse1); 

glLightfv(GL_LIGHT3, GL_POSITION,LightPosition1);

glEnable(GL_LIGHT3); 

glLightfv(GL_LIGHT4, GL_AMBIENT, LightAmbient); 

glLightfv(GL_LIGHT4, GL_DIFFUSE, LightDiffuse2); 

glLightfv(GL_LIGHT4, GL_POSITION,LightPosition2);

glEnable(GL_LIGHT4); 

//end of dump lightning

glDisable(GL_LIGHTING);

//the multicolor quad

glBegin(GL_QUADS); 

glColor3f(0.05f,0.0f,0.0f); 

glVertex3f( 0.0f, 0.0f, 0.0f); 


glColor3f(-0.5f,1.0f,0.0f); 

glVertex3f(0.05f,0.0f, 0.0f); 


glColor3f(0.0f,0.0f,1.0f); 

glVertex3f( 0.05f,0.0f, 0.10f); 

glColor3f(1.0f,0.0f,1.0f); 

glVertex3f( 0.0f,0.0f, 0.10f); 

glEnd(); 


//the pink quad

glColor3f(1.0f,0.0f,1.0f);

glBegin(GL_QUADS);

glVertex3f( 0.1f,0.1f, 0.0f); 

glVertex3f( -0.1f,0.1f, 0.0f); 

glVertex3f( -0.1f,-0.1f, 0.0f); 

glVertex3f( 0.1f,-0.1f, 0.0f); 

glEnd();


//now redrawing the openinventor object to show the difference

if( sceneRoot ) {

sceneRoot->removeChild(camera);

}


SbViewportRegion myViewport(w(), h());

SoGLRenderAction myRenderAction(myViewport);

myRenderAction.apply(sceneRoot);


if( camera ) {

sceneRoot->insertChild(camera, 1);

}


}