nix4dPIX4Ddiscovery is free of charge, unlimited in time and lets Pix4D users process and assess their projects of any size with limited output results. PIX4Ddiscovery is free of charge. To use it, aOpen PIX4Dmatic.; Click File on the menu bar.; Click Open...; On the pop-up Open Project, specify the location of the root.p4m file and click Open. (Optional) If images are not displayed