3D Plot Lighting tab

Enable Diffuse Lighting: Lets you create and adjust the direction of the light. This parameter must be activated to apply light source settings.

Note that when creating a 3D surface plot, if you do not activate Enable Diffuse Lighting and have selected a solid color under the Appearances tab, the 3D object will appear flat.

Inverse Face Normal Orientation: Inverts the direction that the light bounces off the surface of the 3D object. Note that Enable Diffuse Lighting must be activated to activate Inverse Face Normal Orientation.

Light Color: Specifies the color of the point, spot, or directional light.

To specify light color for point, spot, and directional light

1. Activate Enable Diffuse Lighting.

2. Click Light Color.

3. In the ensuing Color dialog box, choose a color for the light.
4. Click OK to close the Color dialog box.

Light Direction: Allows you to specify the direction of the light for Spot light source types. See the Light Source Type parameter for directions on how to specify light direction.

Light Position: Allows you to specify the position of the light for Spot and Point light source types. See the Light Source Type parameter for directions on how to specify light position.

Light Source Type

Directional: Directional light has color and direction that you can control, but not position. The light it generates is referred to as parallel light; that is, all directional light travels through an object in the same direction.

To specify directional light direction using the mouse

1. Activate Enable Diffuse Lighting.

2. Activate Setup Light.

3. Under Light Source Type, activate Spot.

4. Click OK.

In the plot window, a light directional symbol directional%20symbolappears. This symbol represents the light direction. In the upper left corner of the plot window, the x, y, and z coordinates of the direction of the light source are displayed.

5. To control position of the light directional symbol, hold down CTRL+click and drag the mouse.

As you drag the mouse the light directional symbol moves accordingly and sheds light on the 3D object appropriately.

Point: Point light has color and position that you can control; however, it has no single direction. That is, it gives off light equally in all directions.

To specify point light position and range through the dialog box

1. Activate Enable Diffuse Light.

2. Under Light Source Type, activate either Point or Spot.

3. Enter the Light Position coordinates under X, Y, and Z.

4. Under Range, enter a value that indicates how far the light travels.

5. Click OK.

The plot window will reflect the light position you have specified and light the object accordingly.

Spot: Spot light has color, position, and direction that you can control. The light emitted from a spot light has a narrowly focused inner cone of light as well as an outer cone of light. The light intensity diminishes as it reaches the outer cone, and there is no light beyond the outer cone. To control the size of the inner and outer cones, the elements Phi and Theta are used. The following illustration shows the relationship between these elements:

spotlight

To specify spot light position, direction, range Phi, and Theta through the dialog box

Note: You can only enter the range, Phi, and Theta values through the dialog box.

1. Activate Enable Diffuse Light.

2. Under Light Source Type, activate Spot.

3. Enter Light Position coordinates in the corresponding X, Y, and Z text boxes.

4. Enter the Light Direction coordinates in the corresponding X, Y, and Z text boxes.

5. Enter the range, Phi, and Theta values in the corresponding text boxes.

6. Click OK.

The plot window will reflect the light position you have specified and light the object accordingly.

To specify spot light position and direction using the mouse

 

1. Activate Enable Diffuse Lighting.

2. Activate Setup Light.

3. Under Light Source Type, activate Point.

4. Click OK.
In the plot window, a positional/directional symbol Positional%20directional%20symbolappears, which represents the light source. In the upper left corner of the plot window, the X, Y, and Z coordinates of the position and direction of the light source are displayed.

5. To control the position of the light source, h
old down CTRL+right-click and drag the mouse. As you drag the mouse the Positional%20directional%20symbolsymbol moves accordingly and sheds light on the 3D object appropriately.

6. To control the direction of the light source, hold down CTRL+click and drag the mouse. As you drag the mouse, the arrow attached to the Positional%20directional%20symbol symbol moves accordingly and sheds light on the 3D object appropriately.

Phi: Allows you to specify the inner cone of a Spot light source. See the Light Source Type parameter for Phi specifications.

Range: Allows you to specify the range of the light for a Spot light source. See the Light Source Type parameter for light range specification directions.

Setup Light: Lets you control the position and direction of the light using the mouse. For more information, see the Light Source Type parameter.

Theta: Allows you to specify the outer cone of a Spot light source. See the Light Source Type parameter for Theta specification directions.