Free Electron Documented Operators
Common Operator Info
FE SurfaceNormalOp


Adds or replaces normals on the points and/or primitives.


The Input Surface is subject to these changes. An optional Driver Surface can be provided to stabilize the otherwise arbitrary first normal for curve primitives. Currently, the driver's du value is used to align the root normal. As such, a driver must have UV values in order to be useful.

Reference versions of the first two inputs can be specified to help stabilize the normals applied to the root points on curves. If all four inputs are specified, the presumably unanimated Input Reference and Driver Reference are used to find the coordinates on the surface nearest to each root point. These coordinates are then used to find the du values on the presumably animated Driver Surface.


A Point Group can be specified to isolate the effects to the points of a group.

The new data can be created for Point Normals and/or Primitive Normals.

Selecting Custom Point Attribute will write to an alternate Point Attribute. Selecting Custom Primitive Attribute will write to an alternate Primitive Attribute.

If no driver surface is provided, using Follow Bend will try to generate normals pointward from the general bend of the curve. Without this bend estimation, curves start with the Default Normal.

For curves, using Ortho ensures that the normal for each point is perpendicular to the segment connecting that point and the next point (except the last point on the curve which uses the prior segment).


tested in Houdini

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