I have a simple problem, just converting 3D points into 2D image coordinate, the image center should be 0,0 to -1,1 I have done the following equations with the help of @iedoc but I still don't get normalized points also another question how would I debug it, I only have the ability to draw spheres so I can't draw 2D circles First I have camera position and orientation as quaternion, I convert the quaternion to rotation matrix then I compose the camera pose matrix 4x4 that works and I tested it

const Ogre::Vector3 cameraPosition = Stages::StageManager::getSingleton()->getActiveStage()->getActiveCamera()->getCameraWorldPosition();
        const Ogre::Quaternion cameraOrientation =Stages::StageManager::getSingleton()->getActiveStage()->getActiveCamera()->getCameraWorldOrientation();

        Ogre::Matrix4 cameraPose;

        Ogre::Matrix3 orienatationMatrix;

        cameraOrientation.ToRotationMatrix(orienatationMatrix);

        cameraPose[0][0] = orienatationMatrix[0][0];
        cameraPose[1][0] = orienatationMatrix[1][0];
        cameraPose[2][0] = orienatationMatrix[2][0];
        cameraPose[0][1] = orienatationMatrix[0][1];
        cameraPose[1][1] = orienatationMatrix[1][1];
        cameraPose[2][1] = orienatationMatrix[2][1];
        cameraPose[0][2] = orienatationMatrix[0][2];
        cameraPose[1][2] = orienatationMatrix[1][2];
        cameraPose[2][2] = orienatationMatrix[2][2];
        cameraPose[0][3] = cameraPosition.x;
        cameraPose[1][3] = cameraPosition.y;
        cameraPose[2][3] = cameraPosition.z;
        cameraPose[3][0] = 0;
        cameraPose[3][1] = 0;
        cameraPose[3][2] = 0;
        cameraPose[3][3] = 1;

        Ogre::Vector3 pos, scale;
        Ogre::Quaternion orient;

        cameraPose.decomposition(pos, scale, orient);

        std::vector<Ogre::Vector2> projectedFeaturePoints;
        Core::CameraIntrinsics cameraIntrinsics = Core::EnvironmentInformation::getSingleton()->getCameraIntrinsics();
        Core::Resolution screenResolution = Core::EnvironmentInformation::getSingleton()->getScreenResolution();
        Core::EnvironmentInformation::AspectRatio aspectRatio =  Core::EnvironmentInformation::getSingleton()->getScreenAspectRatio();

        Ogre::Matrix4 viewProjection = Stages::StageManager::getSingleton()->getActiveStage()->getActiveCamera()->getCameraViewProjectionMatrix();

        for (int i = 0; i < out.numberofpoints; i++)
        {
            Ogre::Vector4 pt;
            pt.x = out.pointlist[(3*i)];
            pt.y = out.pointlist[(3*i) + 1];
            pt.z = out.pointlist[(3*i) + 2];
            pt.w = 1;

            Ogre::Vector4 pnt = cameraPose.inverse()*pt;

            float x = (((pnt.x - cameraPosition.x)*cameraIntrinsics.focalLength.x)/pnt.z) + cameraPosition.x;
            float y = (((pnt.y - cameraPosition.y)*cameraIntrinsics.focalLength.y)/pnt.z) + cameraPosition.y;

            projectedFeaturePoints.push_back(Ogre::Vector2(x,y));

        }