Chapter 20: Lighting Your World

Understanding Lighting

Point Lights

Figure 20.1


The rays from a point light radiate out from it in all directions.

Directional Lights

Figure 20.2


The rayes from a directional light all project in the same direction..

Spotlights

Figure 20.3


The rays from a spotlight radiate within a strictly defined area.

Coloring Lights

Ambient Light

Light Attenuation

Multiple Lights

The Headlight

Shadows

Lighting Flat Shapes

The PointLight Node Syntax

The DirectionalLight Node Syntax

The SpotLight Node Syntax

Experimenting with Lighting

Creating a Test World

Figure 20.4


A sphere world illuminated by the headlight.

Creating a Test Mesh

Figure 20.5


A flat mesh created using an ElevationGrid node.

Using Point Lights

Figure 20.6a


A sphere world illuminated by a point light in the center. Compare with Figure 20.6b.

Figure 20.6b


A sphere world illuminated from the center by a point light with its ambient intensity set high. Compare with Figure 20.6a.

Figure 20.7


A sphere world illuminated by a point light with attenuation control.

Figure 20.8


A sphere world illuminated by a point light with a small radius.

Building a Glowing Shape Using a Point Light

Figure 20.9


A glowing sphere within a gothic building.

Animating Lights

Figure 20.10


A blinking lightbulb.

Using Directional Lights

Figure 20.11a


A sphere world illuminated by a directional light aiming to the right. Compare with Figure 20.11b.

Figure 20.11b


A sphere world illuminated by a directional light aiming up and to the right. Compare with Figure 20.11a.

Figure 20.12


Two sphere worlds illuminated by two directional lights.

Simulating Sunlight Using a Directional Light

Figure 20.13a


A directional light used to simulate the sun at sunrise. Compare with Figures 20.13b and c.

Figure 20.13b


A directional light used to simulate the sun at noon. Compare with Figures 20.13a and c.

Figure 20.13c


A directional light used to simulate the sun at sunset. Compare with Figures 20.13a and b.

Figure 20.14


The sunlight direction animated using a PositionInterpolator node.

Using Spotlights

Figure 20.15a


A sphere world illuminated by a spotlight in the center aiming to the right. Compare with Figure 20.15b.

Figure 20.15b


A sphere world illuminated by a wide-angle spotlight.

Figure 20.16a


A mesh illuminated by spotlights with inner and outer cones set to 45.0 degrees. Compare with Figures 20.16b and c.

Figure 20.16b


A mesh illuminated by spotlights with the outer cone set to 45.0 degrees and the inner set to 22.5 degrees. Compare with Figures 20.16a and c.

Figure 20.16c


A mesh illuminated by spotlights with the outer cones set to 45.0 degrees and the inner set to 0.5 degrees. Compare with Figures 20.16a and b.

Creating Fake Shadows

Figure 20.17a


A simple world without fake shadows. Compare with Figure 20.17b.

Figure 20.17b


A simple world with fake shadows. Compare with Figure 20.17a.

Summary