- Also improved functionality of npdet_fields
```
SYNOPSIS
        npdet_fields [-vi] draw [--Nsteps <Nsteps>] [--step <step>] [--start <x> <y> <z>] [--end <x1> <y1> <z1>] [-l <level>...] <file> [-h]
        npdet_fields [-vi] draw [--Nsteps <Nsteps>] [--step <step>] [--start <x> <y> <z>] [--direction <x2> <y2> <z2>] [-l <level>...] <file> [-h]
        npdet_fields [-vi] (print|dump) [--all] [--replace] [-f] <file> [-h]
        npdet_fields [-vi] list <file> [-h]
```