Lighting in 3D design refers to the placement, adjustment, and configuration of light sources in a 3D scene to create depth, mood, and realism. Proper lighting is crucial for making 3D objects appear three-dimensional and visually appealing.

Types of lighting:

- Directional light: Simulates sunlight (parallel rays)

- Point light: Light from a single point (like a lightbulb)

- Spotlight: Focused cone of light

- Ambient light: General scene illumination

- Area light: Large light source for soft shadows

Lighting properties:

- Intensity: Brightness of the light

- Color: Color temperature (warm/cool)

- Position: Where the light is placed

- Direction: Which way light travels

- Shadows: How objects block light

Lighting techniques:

- Three-point lighting: Key, fill, and rim lights

- Global illumination: Realistic light bouncing

- HDR lighting: High dynamic range for realism

- Ambient occlusion: Soft shadows in corners

Good lighting:

- Creates depth and dimension

- Highlights important features

- Sets the mood and atmosphere

- Makes objects look realistic

- Guides viewer attention

In 3D icon design, lighting helps icons stand out and appear professional, making them more engaging and easier to recognize.