Tuesday, September 22, 2009
2.5 Pivot Points
Hi. The goal of this video is to get you comfortable moving around in Blender 2.5. If you're going to continue with Blender, 2.5 will be your new home. The developers just made 2.5 the official "trunk" for Blender development. That means that future development will be exclusively in 2.5. Work on older versions will, most likely, be limited to bug fixes and, as 2.5 becomes the standard.
Scaling and rotating objects are a fundamental Blender skill. The pivot point defines how objects will be rotated and scaled. If you're relatively new to Blender, you can easily get objects moving in ways you might not expect. As we progress, I will point out differences between Blender 2.5 and the older versions. The pivoting actions really haven't changed in 2.5. However, some cosmetic things like the default color of the active object and the icons for rotation and scaling, have changed. You should feel very comfortable pivoting your way in 2.5 almost immediately.
We start with the default Blender scene. First, we delete the default cube. Before, you could either use the delete key or press X. In 2.5, only X works. The delete key does nothing. So press X and confirm the delete.
We'll add the monkey object, by pressing the SPACE key. Something happens, but it's not what you expect. You get a different menu than before, a menu that has nothing to do with adding objects. Press ESC. We'll save discussion of that menu for another time. Instead, press Shift-A, which is the keyboard shortcut for adding objects. Shift-A brings up the familiar object add menu. Select Add-Mesh-Monkey, as before.
Let's look at the outliner window, in the upper right corner of the screen, and scroll down. Guess what? Suzanne isn't there. She has been renamed "Mesh". I guess they'll have to rename the Suzanne Award.
We'll create 3 monkey objects to demonstrate rotation. First, duplicate our monkey - it will take a bit of time getting used to the name "Mesh" - with Shift-D. Shift-D works as before. We grab the copy and move it away from the original, and left click to confirm. Then we press Shift-D to create another copy and drag it to form a triangle of monkeys.
Switch to Quad View, a new built in view, by going to the View menu, and selecting Toggle Quad View. The window is divided into 4 windows, Top, Front, Right, and Camera, that make it, in my opinion, much easier to navigate around your scene than before. Since Toggle Quad View is a toggle, by selecting Toggle Quad View again, you get back to the startup scene, with just one 3D window.
We'll work in Quad View. Adjust the monkeys positions so that they look right in Top View and Camera View. We'll work in Top View. Select the first monkey with right click. Then hold down the Shift key, Right Click, and select the second monkey. Hold down the Shift key, Right click, and select the third monkey. Note that the default color for the selected object and the active object - the last one you selected, and the name that displays in the lower left hand corner - has changed from pink to orange. I think orange is much easier to see. The active object has a light orange border, as opposed the light pink in the older Blender versions.
The default pivot mode is Bounding Box center, which means that the pivot point is defined by the bounding box. The Move Object Centers Only is off by default, as before. Press the R key to rotate the monkeys. Note that the rotation icon is double arrows, and that the monkeys rotate around the bounding box center. Pressing Escape cancels the rotation, as before.
Just for fun, press the R key twice (R and R). This allows you to rotate in 3 dimensions. It's a neat feature and not very well known. Press Esc to cancel.
Turn the Move Object Centers button on. This makes rotation and scaling affect the object center only, not the objects themselves. Now press the R key and rotate. The monkeys do not tilt as they rotate. Press Esc to cancel the rotation, and turn off the Move Object Centers Only button.
Now press S to scale. With the Move Object Centers Only button inactive, all the monkeys grow or shrink. Press Esc to cancel the scaling. Now turn on the Move Object Centers Only button and press the S key. Now, the monkeys don't grow or shrink, BUT they do get nearer or farther away from each other while preserving their relative position. This is useful for repositioning objects in your scene. Press Esc and turn off the Move Object Centers Only button.
Now open the Pivot Menu and select Active Object as your pivot point. Press R to rotate. Now the monkeys tilt while they rotate around the active object, similar to the bounding box behavior. Press Escape to cancel.
Turn on the Move Object Centers Only button and press the R key. Now the monkeys keep facing forward as they rotate around the active object. Press Esc to cancel the rotation, and turn off Move Object Centers Only.
Press the S key to scale. The monkeys grow and shrink. Press ESC to cancel the scaling. Turn on the Move Object Centers Only button and press the S key. Now the monkeys move away from or closer to each other but do not grow or shrink. Press ESC to cancel. Turn off the Move Object Centers Only button.
Open up the Pivot Menu and select Individual Centers as your pivot point. Press R to rotate. Each monkey rotates around its center point. Press Esc and turn on the Move Object Centers button. Now when you press R to rotate, nothing happens. That's because only the centers (all 3 of them) rotate. The monkeys don't do anything. Press Esc to cancel.
Turn off the Move Object Centers button and press S to scale. Now the monkeys grow and shrink in unison, like a dance line. Press Esc to cancel and turn on the Move Object Centers button. Again, the monkeys don't do anything because only the centers scale, and each of them is only a point to begin with. Press Esc to cancel and turn off the Move Object Centers button.
Open up the Pivot Menu and select 3D Cursor as your pivot point. The behavior of rotation and scaling is the same as for Bounding Box and Active Object, except that the pivot is around wherever the 3D cursor is situated.
Our final pivot point type, Median Point, is the center point for all the selected objects. This is similar to Bounding Box center, except that the median point might be, and usually is, different from the bounding box center because objects tend to have different sizes. As you see, the behavior is similar, but the pivot point is slightly different.
To summarize, pivoting is basically the same as before. However, because of the new Quad View, the better choice of colors and icons, and the improved design of the startup screen, it's much easier to see what's going on.