private Matrix4f calculateProjection(int eye, Camera cam) {
        Matrix4f mat = new Matrix4f();

        // Get LibOVR to find the correct projection
        OVRUtil.ovrMatrix4f_Projection(fovPorts[eye], cam.getFrustumNear(), cam.getFrustumFar(), OVRUtil.ovrProjection_None, projections[eye]);

        matrixO2J(projections[eye], mat);

        return mat;
    }
Frame buffers we can draw into.
jme3-vr/src/main/java/com/jme3/input/vr/oculus/OculusVR.java