Camera Opengl to OSG or with MatrixTransfrom

[Daoudou]

Hello all

I have some questions.

I want to transmit the camera of my opengl scene to my OSG scene, to do this I retrieve the view of my camera as well as the point it is looking at with the following code:

{
GLdouble camera_pos[3];

    double rationZoom    = m_pModel->GetView()->m_graphEnv.GetZoomRatio();
    int* iViewport       = m_pModel->GetView()->m_graphEnv.GetViewport();
    double* projetMatrix = m_pModel->GetView()->m_graphEnv.GetProjMatrix();
    double* modelMatrix  = m_pModel->GetView()->m_graphEnv.GetModelMatrix();

    double screenCenterX = m_pModel->GetView()->m_graphEnv.GetScreenCenterX();
    double screenCenterY = m_pModel->GetView()->m_graphEnv.GetScreenCenterY();
   
    double rotateX = m_pModel->GetView()->m_graphEnv.GetRotationCenterX();
    double rotateY = m_pModel->GetView()->m_graphEnv.GetRotationCenterY();
    double rotateZ = m_pModel->GetView()->m_graphEnv.GetRotationCenterZ();

// I retrieve the camera and the center of the screen (for the point it is looking)
gluUnProject((iViewport[2] - iViewport[0]) / 2, (iViewport[3] - iViewport[1]) / 2,
0.0, modelMatrix, projetMatrix, iViewport, &camera_pos[0], &camera_pos[1], &camera_pos[2]);

    // rotCenter it's the center point looking
    osg::Vec3f rotCenter = osg::Vec3f(screenCenterX,
                                      screenCenterY,
                                      rationZoom * (-1.0));

    double X = (camera_pos[0] / 2) / rationZoom;
    double Y = (camera_pos[1] / 2) / rationZoom;
    double Z = (camera_pos[2] / 2) / rationZoom;

   osg::Vec3 updateCameraPosition(X, Y,Z);

    osg::Vec3f eye(updateCameraPosition);

    osg::Vec3f up(0, 0, 1);
    osg::Vec3f centre = osg::Vec3f(rotCenter.x(), rotCenter.y(), rotCenter.z());
    nodeCamera->setViewMatrixAsLookAt(eye, centre, up);

}

but i don't know why, i have wrong values with osg eye Y axis. Does anyone have any ideas ??

If I'm not mistaken the OpenGL coordinate system is : Y up, X right, Z forward but I don't have this configuration on my OSG scene. Maybe this is the problem ?

Or I have to use Matrix Transform and rotate the matrix to have the same coordinate system of my OpenGL scène ?? So can I set matrixtransform with my camera and set it to my viewer ??

Thanks in advance
Souffou

[robertosfield]

I would have thought you could just the complete projection and modelview matrices from the GL side and assign them to the osg::Camera's view and projection martrices.

[robertosfield]

You don't need to go through the LookAt functions, the matrices can be applied directly.

FYI, the Camera::setViewMatrix(matrix) sets the matrix directly, the Camera::setViewMatrixAsLookAt(..) generates the matrix based on the gluLookAt convention and then calls Camera::setViewMatrix.

[Daoudou]

Thanks but i want to know , my camera must constantly receive information from the OpenGL camera then there is no problem if I recalculate the projection matrix? My program crashes if this is the case.

[Daoudou]

My problem is about the thread OpenThread, Thanks if i solve this problem everything works.