Regions in Blender
Regions are areas in an editor that give you additional tools specific to that editor. In Blender, the header, for example, is one type of region. The figure shows the other two regions in Blender’s 3D View.
Flanking either side of the 3D View is a Tool Shelf on the left, and on the right is a region for modifying the properties of the 3D View, referred to as the Properties region or the Information region.
The Properties/Information region
You can toggle the visibility of the Properties region by going to View→Properties in the header or by pressing N (for iNformation) while your mouse cursor is in the 3D View. In fact, quite a few editors in Blender have a Properties region. And with the exception of the Text Editor, you can consistently open all of them by using the N hotkey.
In the 3D View, the Properties region serves two primary purposes. Most obviously, it allows you to directly modify your selected object by typing in explicit location, rotation, and scale values within the Transform panel. The rest of the region, however, is dedicated to customizing your 3D View.
From here, you can control features like the location of the 3D cursor, which axes are displayed, the appearance of the grid floor, and the shading mode used for the Textured Viewport Shading type (Multitexture or GLSL). This region is also where you go if you want to load a background image in the 3D View as a modeling reference.
Because Blender has a Properties editor as well as a Properties region, you may find it useful to think of the Properties region as an Information region instead. It’s a game of semantics, but by thinking of it as an Information region, the N hotkey is easier to remember.
The Tool Shelf
The real gem of a region within the 3D View is the Tool Shelf, shown on the left of the 3D View by default. You can toggle the Tool Shelf’s visibility by going to View→Tool Shelf in the header or by using the T hotkey.
Think of the Tool Shelf as a place for frequently used tools or operators. Most of these operators also are accessible by hotkey or some other menu, but having shortcuts in the Tool Shelf is extremely helpful for helping you work faster, especially if you haven’t memorized all of Blender’s various hotkeys. This way, frequently used tools are only a single click away rather than the multiple clicks it might take you to hunt through the menu system. And when it comes to Blender’s sculpting and painting tools, the Tool Shelf is indispensable.
The Tool Shelf holds an additional feature that’s extremely useful. At the bottom of the Tool Shelf is the Last Operator panel. If you’ve just opened Blender, this panel should just have the heading of Operator. However, if you perform an action in Blender like moving your selected object or adding a new object, this panel updates to display values relevant to that operation.
Using this panel, you can perform a quick, rough operation and then tweak it to be more precise. For example, if you add a UV Sphere to your scene (Shift+A→Add Mesh→UV Sphere), Blender adds a UV Sphere object to your scene at the location of the 3D cursor with 32 segments and 24 rings. Using the Last Operator panel of the Tool Shelf, you can not only adjust the location of your new sphere, but you can also modify the number of segments and rings it has.
If you happen to have the Tool Shelf hidden, you can still access the last operator panel by pressing F6. Upon doing so, a “floating” Last Operator appears under your mouse cursor. The figure shows the floating last operator panel after adding a UV sphere to the scene.
You should note that the Last Operator panel is only relevant for the last operation you actually performed. It’s not a construction history, and it doesn’t persistently remain in memory after you perform subsequent operations. For example, if you add a UV Sphere and then immediately rotate that sphere, there’s no way for you to adjust the number of segments and rings in it from the Last Operator section. Even if you undo the rotate operation, those Last Operator values won’t return (after all, Undo is another operation). The Last Operator section relates to the last thing you did — no more, no less.