Cameras

Rendering a scene means looking at the scene from the viewpoint of a camera, calculating the view, and recording it in an image file. The camera is part of the scene, just like lights and geometric objects, and has its own instance that defines its position and orientation in 3D space, again just like lights and objects. Unlike objects, however, the camera instance must be attached to the root group, to prevent multiple instancing of the camera. The scene cannot be rendered from multiple viewpoints simultaneously. It is, however, possible to define multiple cameras and attach their camera instances to the root group; the one to be used must be passed to the render statement. See the simple cube example on page 26 for a very simple scene setup.