Outline the ways that lights can be established in a viewport.

What will be an ideal response?

There are five categories of virtual lighting: spotlights, point light, directional light, rectangular light, and linear light. A spotlight is characterized by a light source emitting a conical beam of light toward a target. It illuminates a conical volume in the scene. In the scene, a spotlight is represented by two cones with a common vertex. They represent the direction of the light, not the range of the light. The inner cone represents the area of full brightness of the light, and brightness will decrease from the inner cone toward the outer cone. A point light is analogous to an ordinary electric light bulb that emits light in all directions. Point light illuminates an entire scene. Directional lighting derives from a light source at a distance, such as the sun. This lighting, generally represented as a beam or parallel beams of light, illuminates an entire scene. Rectangular lighting simulates the effect of a fluorescent light box. You specify the location, width, and length of the rectangular light. Linear light simulates the effect of a fluorescent tube being added to a scene. You specify the start point and the end point of the linear fluorescent light.