sn: DISPATCH snapshot object.
path: Output directory; created if needed.
mode: Grid type; accepted values are 'cartesian' ('grid_style_0'), or 'octree' ('grid_style_1').
density: Density variable or expression key, typically 'd'.
dust_fraction: Scalar multiplier applied before writing dust_density.binp.
temperature: Compatibility alias for Tdust.
Tdust: Optional dust-temperature for dust_temperature.bdat; accepts a p.var() slot or an attached patch array.
Tgas: Optional gas-temperature for gas_temperature.binp; accepts a p.var() slot or an attached patch array.
velocity: Optional 3-tuple of variable keys for gas_velocity.binp
center: Optional 3-vector giving the export-box center in code units.
sink: Optional sink ID; if both sink and center are given, the exporter uses sink.
npix: Optional export size at levelmax; scalar => isotropic, 2 values => x and y + full z, 3 values => 3-D size.
width: Optional export width in code units; similar to npix
levelmax: Optional maximum DISPATCH patch level; finer patches are ignored.