surfl (MATLAB Functions)

Surface plot with colormap-based lighting

Syntax

surfl(Z)
surfl(X,Y,Z)
surfl(...,'light')
surfl(...,s)
surfl(X,Y,Z,s,k)
h = surfl(...)

Description

The surfl function displays a shaded surface based on a combination of ambient, diffuse, and specular lighting models.

surfl(Z) and surfl(X,Y,Z) create three-dimensional shaded surfaces using the default direction for the light source and the default lighting coefficients for the shading model. X, Y, and Z are vectors or matrices that define the x, y, and z components of a surface.

surfl(...,'light') produces a colored, lighted surface using a MATLAB light object. This produces results different from the default lighting method, surfl(...,'cdata'), which changes the color data for the surface to be the reflectance of the surface.

surfl(...,s) specifies the direction of the light source. s is a two- or three-element vector that specifies the direction from a surface to a light source. s = [sx sy sz] or s = [azimuth elevation]. The default s is 45° counterclockwise from the current view direction.

surfl(X,Y,Z,s,k) specifies the reflectance constant. k is a four-element vector defining the relative contributions of ambient light, diffuse reflection, specular reflection, and the specular shine coefficient. k = [ka kd ks shine] and defaults to [.55,.6,.4,10].

h = surfl(...) returns a handle to a surface graphics object.

Remarks

For smoother color transitions, use colormaps that have linear intensity variations (e.g., gray, copper, bone, pink).

The ordering of points in the X, Y, and Z matrices defines the inside and outside of parametric surfaces. If you want the opposite side of the surface to reflect the light source, use surfl(X',Y',Z'). Because of the way surface normal vectors are computed, surfl requires matrices that are at least 3-by-3.

Examples

View peaks using colormap-based lighting.

[x,y] = meshgrid(-3:1/8:3);
z = peaks(x,y);
surfl(x,y,z);
shading interp
colormap(gray);
axis([-3  3  -3  3  -8  8])

To plot a lighted surface from a view direction other than the default,

view([10 10])
grid on
hold on
surfl(peaks)
shading interp
colormap copper
hold off

See Also

colormap, shading, light

Creating Surfaces and Meshes for functions related to surfaces

Lighting for functions related to lighting

Surfaceplot Properties surfnorm