fixed marker dragging over map when tilt and roll are not zeroes

    var at = from.subtract(mat.e2());

    var up = mat.e1();

    var newfrom = delta;

    // corrections

    var R0 = Data.camera.Matrices.R0;

    var from_tmp = R0.multMatrixVec(from);

    var delta_tmp = R0.multMatrixVec(delta);

    // keeping height

    newfrom.y = from.y;

    delta_tmp.y = from_tmp.y;

    var newfrom = R0.inverse().multMatrixVec(delta_tmp);

    var newat = newfrom.subtract(mat.e2());

    var newmat = x3dom.fields.SFMatrix4f.lookAt(newfrom, newat, up);

    x3dom_setViewpoint(newmat);

function x3dom_altelev(alt,elev){

    console.log("setting elevation");

    //x3dom_matrix_test();

    var mat = Scene.element.runtime.viewMatrix().inverse();