This commands creates an isosurface Maya mesh for the selected Maya mesh(es), by adding a zIsoMesh node to the selected Maya mesh(es).:

zIsoMesh ...
  -h     -help                         <n/a>       this message
  -imv   -isoMeshIsosurfaceValue       <float>     set the isosurface value (default: good automatic value) (can be positive, zero, or negative)
  -ims   -isoMeshTriangleSize          <float>     set the triangle size (default: 2) (must be > 0)
  -imr   -isoMeshResolution            <int>       set the resolution (default: 64)
  -imp   -isoMeshPrecision             <int>       set the precision (0: double, 1: exact) (default: 0)
  -imm   -isoMeshProduceManifoldMesh   <bool>      whether to post-process the output towards a manifold mesh (default: true)
  -imi   -isoMeshLimitMaxIterations    <bool>      whether to limit the maximum number of iterations (default: true)
  -imI   -isoMeshMaxIterations         <int>       maximum number of iterations (default: 10000)
  -imt   -isoMeshLimitMaxTime          <bool>      whether to limit the maximum running time (default: true)
  -imT   -isoMeshMaxTime               <float>     maximum running time (in seconds) (default: 60)

Usage example:
Select a Maya mesh and then execute:

The command will return the name of the created node(s)