pyvista.PolyDataFilters.flip_normal_vectors

PolyDataFilters.flip_normal_vectors(

*,

inplace: bool = False,

progress_bar: bool = False,

)

Flip the direction of the mesh’s point and cell normal vectors.

This filter effectively multiplies the point and cell normals by -1. It has no effect if no active normals are currently set.

Note

Polygon cells have an implicitly-defined orientation which may differ from the orientation of the normal vectors. To ensure that the normals are consistent with this implicit definition, consider also using flip_faces() or re-computing normals with compute_normals() and enabling the flip_normals option.

Added in version 0.45.

Parameters:

inplacebool, default: False

Overwrites the original mesh in-place.

progress_barbool, default: False

Display a progress bar to indicate progress.

Returns:

pyvista.PolyData

Mesh with point and cell normal directions flipped.

See also

pyvista.PolyDataFilters.flip_faces

Flip the orientation of the faces.

pyvista.PolyDataFilters.compute_normals

Compute new normals. Includes the option to flip the normals.

pyvista.PolyData.point_normals

Returns the array of point normals.

pyvista.PolyData.cell_normals

Returns the array of cell normals.

Examples

Flip the normal vectors of a sphere. Show one of the normal vectors before and after the flip.

>>> import pyvista as pv
>>> sphere = pv.Sphere()
>>> sphere.point_data['Normals'][0]
pyvista_ndarray([0., 0., 1.], dtype=float32)

>>> sphere_flipped = sphere.flip_normal_vectors()
>>> sphere_flipped.point_data['Normals'][0]
pyvista_ndarray([-0., -0., -1.], dtype=float32)

Note that the sphere’s cell ordering has not been affected by this filter.

>>> sphere.regular_faces[0]
array([ 2, 30,  0])

>>> sphere_flipped.regular_faces[0]
array([ 2, 30,  0])