The main focus of AutoCAD 2007 is 3D modeling and visualization. There have been improvements in being able to create and edit 3D solids and surfaces, but what about visualization. AutoCAD 2006 had a feature called Crop Window in the Render dialog box, which shows a region of the scene fully rendered. This feature is a little more obvious in AutoCAD 2007 as it easier to access, but it also has been improved. In AutoCAD 2006 anything that was outside of the cropped region was not displayed, but in AutoCAD 2007 the other objects remain displayed in the viewport allow you to create interesting presentation drawings. Only one region can be rendered at a time, and the previous region is refreshed before the new cropped region is rendered. This can be great for testing lighting and shadows in a scene before doing a full render which can take much longer.