Setting Lighting Effects

This tasks explains how to vary ambient lighting effects using directional light sources (i.e. light sources coming from a given direction, generating constant-intensity parallel lighting).
  1. Select View > Lighting to display the Light Sources dialog box.

    The default light source settings look like this...
    ... and produce a lighting effect, for example, like this:
    Note that Single Light is activated by default. The sphere indicates the current lighting direction. The handle on the sphere indicates the direction from which the light is being projected: by default, the light is coming from the top left.

    You can drag the handle around (using the left mouse button) to change the lighting direction. The new lighting effect is created instantaneously as you drag the handle.

    The three sliders at the bottom of the dialog box control respectively (from top to bottom):
    • Ambient coefficient: defines the intensity of light emitted in any direction by the object, even if not lit by any light source. The ambient light is essentially used to show objects or parts of objects that are not illuminated directly by the light source.

     Ambient = 0.50

    Ambient = 1.00

    • Diffuse coefficient: defines the intensity of light diffused by the object when lit by a light source:

    Diffuse = 0.50

    Diffuse = 1.00

    • Specular coefficient: defines the intensity of light reflected in one particular direction. This coefficient affects the highlight on shiny surfaces. The higher the value, the bigger the the specular spot:

    Specular = 0.50

    Specular = 1.00

    To define the desired value, you can drag the desired slider or use the spin box next to it either by clicking the up and down arrows or by entering a value directly in the field.
  2. Drag the handle down and towards the bottom right: the light is now coming from the bottom right:

  3. Click Two Lights to add another light source.

    In our example, using two light sources means that the lighting is now too bright.
  4. Drag the brightness slider (the first slider in the list) to the left or use the spin box next to it to reduce the brightness.

  5. Now, drag the lower handle up towards the top left to change the direction of the corresponding light source:

  6. Click Neon Light to produce a neon light effect.

  7. Click No Light to switch off all light sources.

Using the Color Chooser To Color Light Sources

You can also color light sources using the color chooser.
  1. Double-click a light source handle.

    The Color chooser appears:

    The colored area with the cross represents a color spectrum.

  2. Drag the cross inside the spectrum to instantaneously change the color in the small box below the spectrum.

    The HSL (Hue, Saturation and Luminance) and RGB (Red, Green and Blue) values vary according to where the cross is located. You can also enter HSL and RGB values in the fields provided to suit your exact color specifications.
    • Hue: name by which the color is designated.
    • Saturation: color intensity.
    • Luminance: color brightness.

    HSL is an alternate model to RGB model for color specification and is illustrated by the scheme below:

  3. Move the arrow up or down to vary the brightness of the custom color:

  4. Click Apply or OK to apply the changes.