Edit Surface - Lights
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Select surface > Editor > Edit Surface > Lights

Use to customize number, position, color, and brightness of the lights illuminating a 3D surface plot.

Note

Lighting options do not affect wireframe plots. You can also alter light positions using the light rotation buttons on the 3D Graph Tools toolbar.

Dialog box items

Automatic: Choose to accept the default surface lighting.

Custom: Choose customize the surface lighting.

On: Check to turn on the light so that it illuminates the data surface. You can have up to three lights.

Relative Position Control the location of the light relative to the center of the graph space. Type a larger number to move the light in the positive direction parallel to the axis. Type a smaller number to move the light parallel to the axis in the negative direction. See below for illustrations and additional information.

X: Type a number for the x-coordinate.

Y: Type a number for the y-coordinate.

Z: Type a number for the z-coordinate.

Color: Choose a color for the light.

Brightness: Type a value between 0 (darkest) and 100 (brightest) to control the brightness of all lights. See below for an illustration.

<Attributes>

<Method>

More on Relative Position <back to top>

The x-, y-, and z-coordinates for light position are expressed relative to the center of the data region, which is coordinate 0 0 0. Coordinate units are designed to be consistent between x, y, and z, and are thus not related to the data measurement units.

The red dot above the graph in the figure at left represents Light 1 in its default position. The blue dot represents Light 2 in its default position. The coordinates for these positions are:

Light     X     Y     Z

  1       0     1     1

  2       0     0    -1

Light 1 is positioned in the center of the graph space with respect to the x-axis (x = 0), but one unit in the positive direction with respect to both the y- and z-axes (y = 1 and z = 1). This gives it the appearance of being above and somewhat behind and to the right of the graph.

Light 2 is positioned directly below the graph space, centered with respect to the x- and y-axes (x = 0 and y = 0), but one unit in the negative z direction (z = -1).

 

 

In the figure at left, x and y for Light 1 have been set to zero, so it is centered directly above the graph:

Light     X     Y     Z

  1       0     0     1

  2       0     0    -1

Notice that the red light illuminates more of the nearer face of the graph than in the previous figure.

 

 

In this next figure (left), z for Light 1 has been increased to 2, so it is higher above the graph:

Light     X     Y     Z

  1       0     0     2

  2       0     0    -1

Notice this has the effect of spreading the red illumination across more of the inverted bowl-shaped surface.

More on Brightness <back to top>

Use Brightness to change the intensity of the lighting for a 3D surface plot. Lower values result in darker surfaces, higher values result in lighter surfaces.

Brightness = 50.

Brightness = 80.