The previous chapters introduced you to group, property, and shape nodes and showed you how to create a scene graph using these nodes. Now you'll move on to two classes of nodes that affect how the 3D scene appears: lights and cameras. In Inventor, as in the real world, lights provide illumination so that you can view objects. If a scene graph does not contain any lights and you're using the default lighting model (Phong lighting), the objects are in darkness and cannot be seen. Just as the real world provides a variety of illumination types—light bulbs, the sun, theatrical spotlights—Inventor provides different classes of lights for you to use in your scene.
Cameras are our “eyes” for viewing the scene. Inventor provides a class of camera with a lens that functions just as the lens of a human eye does, and it also provides additional cameras that create a 2D “snapshot” of the scene with other kinds of lenses. This chapter discusses cameras first and assumes that the scene has at least one light at the top of the scene graph.
![[Tip]](../images/tip.jpg) | |
Tip: Viewer components create their own camera and light automatically. See Chapter 18, Open Inventor Component Library for more information on viewers. |