Filling the invoice form from saleOder

When I generate an invoice from a saleOder, the invoice is filled automatically. My problem is that i have added some fileds in the saleOrder and the SaleOrderLine but i don’t find a way to display my new fields with their content in the invoice. Any idea?

Have you created new modules to add fields ?.
If yes then you have to override view and process that generate invoice from order.