Normals Generation (PolyDataNormals)
This filter will produce surface normals used for smooth shading. Spltting is used to avoid smoothing across feature edges.
The Normals generation filter generates surface normals at the points of the input polygonal dataset to provide smooth shading of the dataset. The resulting dataset is also polygonal. The filter works by calculating a normal vector for each polygon in the dataset and then averaging the normals at the shared points.

PropertyDescriptionDefault Value(s)Restrictions
Compute Cell Normals
(ComputeCellNormals)
This filter computes the normals at the points in the data set. In the process of doing this it computes polygon normals too. If you want these normals to be passed to the output of this filter, set the value of this property to 1. 0

Only the values 0 and 1 are accepted.

 
Consistency
(Consistency)
The value of this property controls whether consistent polygon ordering is enforced. Generally the normals for a data set should either all point inward or all point outward. If the value of this property is 1, then this filter will reorder the points of cells that whose normal vectors are oriented the opposite direction from the rest of those in the data set. 1

Only the values 0 and 1 are accepted.

 
Feature Angle
(FeatureAngle)
The value of this property defines a feature edge. If the surface normal between two adjacent triangles is at least as large as this Feature Angle, a feature edge exists. If Splitting is on, points are duplicated along these feature edges. (See the Splitting property.) 30

The value must be greater than or equal to 0 and less than or equal to 180.

 
Flip Normals
(FlipNormals)
If the value of this property is 1, this filter will reverse the normal direction (and reorder the points accordingly) for all polygons in the data set; this changes front-facing polygons to back-facing ones, and vice versa. You might want to do this if your viewing position will be inside the data set instead of outside of it. 0

Only the values 0 and 1 are accepted.

 
Input
(Input)
This property specifies the input to the Normals Generation filter.  

The selected object must be the result of the following: sources (includes readers), filters.

The selected dataset must be one of the following types (or a subclass of one of them): vtkPolyData.

 
Non-Manifold Traversal
(NonManifoldTraversal)
Turn on/off traversal across non-manifold edges. Not traversing non-manifold edges will prevent problems where the consistency of polygonal ordering is corrupted due to topological loops. 1

Only the values 0 and 1 are accepted.

 
Piece Invariant
(PieceInvariant)
Turn this option to to produce the same results regardless of the number of processors used (i.e., avoid seams along processor boundaries). Turn this off if you do want to process ghost levels and do not mind seams. 1

Only the values 0 and 1 are accepted.

 
Splitting
(Splitting)
This property controls the splitting of sharp edges. If sharp edges are split (property value = 1), then points are duplicated along these edges, and separate normals are computed for both sets of points to give crisp (rendered) surface definition. 1

Only the values 0 and 1 are accepted.