NormalsFunction
✖
NormalsFunction
is an option for Plot3D and related functions that specifies a function to apply to determine the effective surface normals at every point.
Details

- The following settings can be given:
-
None determine normals from explicit polygon vertices Automatic determine normals from overall surface properties f determine normals by applying a function f - With NormalsFunction->f, the arguments supplied to f are as follows:
-
Plot3D x, y, z ParametricPlot3D x, y, z, u, v ContourPlot3D x, y, z, w RegionPlot3D x, y, z - The function f must return a vector of the form {vx,vy,vz}. Only the direction of this vector matters; the vector is in effect automatically normalized to unit length.
Examples
Basic Examples (3)Summary of the most common use cases
Use automatic methods to compute surface normals:

https://wolfram.com/xid/0h2pmr4t4y-l4xol6

Make the effective normals to the surface vary locally:

https://wolfram.com/xid/0h2pmr4t4y-bflswj

Use flat shading for all polygons:

https://wolfram.com/xid/0h2pmr4t4y-exc156

Wolfram Research (2007), NormalsFunction, Wolfram Language function, https://reference.wolfram.com/language/ref/NormalsFunction.html.
Text
Wolfram Research (2007), NormalsFunction, Wolfram Language function, https://reference.wolfram.com/language/ref/NormalsFunction.html.
Wolfram Research (2007), NormalsFunction, Wolfram Language function, https://reference.wolfram.com/language/ref/NormalsFunction.html.
CMS
Wolfram Language. 2007. "NormalsFunction." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/NormalsFunction.html.
Wolfram Language. 2007. "NormalsFunction." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/NormalsFunction.html.
APA
Wolfram Language. (2007). NormalsFunction. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/NormalsFunction.html
Wolfram Language. (2007). NormalsFunction. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/NormalsFunction.html
BibTeX
@misc{reference.wolfram_2025_normalsfunction, author="Wolfram Research", title="{NormalsFunction}", year="2007", howpublished="\url{https://reference.wolfram.com/language/ref/NormalsFunction.html}", note=[Accessed: 08-July-2025
]}
BibLaTeX
@online{reference.wolfram_2025_normalsfunction, organization={Wolfram Research}, title={NormalsFunction}, year={2007}, url={https://reference.wolfram.com/language/ref/NormalsFunction.html}, note=[Accessed: 08-July-2025
]}