How to show data in input with angular?

The idea is that pressing the "Edit" button will show the data in the inputs, but I can not find the error

<tr>
                    <td><input class="form-control" ng-model='materiales.codigo'></td>
                    <td><input class="form-control" ng-model='materiales.nombre'></td>
                    <td><input class="form-control" ng-model='materiales.stock'></td>
                    <td><button class="btn btn-primary" ng-click='addmateriales()'>Agragar Material</button></td>
                    <td><button class="btn btn-info" ng-click='update()'>Actualizar</button></td>
                </tr>
                <tr ng-repeat="materiales in listamaterial">
                    <td>{{materiales.codigo}}</td>
                    <td>{{materiales.nombre}}</td>
                    <td>{{materiales.stock}}</td>
                    <td><button class="btn btn-danger" ng-click="remove(materiales._id)">Remover</button></td>
                    <td><button class="btn btn-warning" ng-click="edit(materiales._id)">Editar</button></td>

$scope.remove = function(id){
    console.log(id);
    $http.delete('/listamaterial/' + id).then(function(response){
        refresh();
    });
};

$scope.edit = function(id){
    console.log(id);
    $http.get('/listamaterial/' + id).then(function(response){
        $scope.materiales = response;
    });
};

app.delete('/listamaterial/:id', function(req, res){
    var id= req.params.id;
    console.log(id);
    db.panol.remove({_id: mongojs.ObjectId(id)}, function(err, doc){
        res.json(doc);
    })
});

app.get('/listamaterial/:id', function(req, res){
    var id = req.params.id;
    console.log(id);
    db.panol.findOne({_id: mongojs.ObjectId(id)}, function(err , doc){
        res.json(doc);
    });
});