Use model.component(<ctag>).mesh(<tag>).create(<ftag>,"FreeTet") to create an unstructured tetrahedral mesh.
 
    Use model.component(<ctag>).mesh(<tag>).feature(<ftag>).selection() to specify the domain selection. If you do not specify any selection the feature creates a mesh on the remaining geometric entities.
 
    Use model.component(<ctag>).mesh(<tag>).feature(<ftag>).create(<ftag1>,ftype) to add attribute features.
 
    The method property determines the Delaunay tessellation algorithm to use. The default is 
auto, which makes the 
FreeTet mesh generator determine the best algorithm for each domain. The 
del1 Delaunay algorithm is the Delaunay algorithm used in earlier COMSOL versions. The 
del2 Delaunay algorithm is an alternative version of the algorithm, which under some conditions can modify the boundary mesh to simplify the meshing.
 
    The properties xscale, 
yscale, and 
zscale specify scalar factors in each axis direction that the geometry is scaled by before meshing. The resulting mesh is then scaled back to fit the original geometry. The values of other properties correspond to the scaled geometry. By default, no scaling is done.
 
    For imported meshes, there is a default size attribute under the FreeTet feature with the tag size. You can access it using 
model.component(<ctag>).mesh(<tag>).feature(<ftag>).feature("size").