Tip

When you animate, it’s better if you have a powerful computer, but more important is that your scene is optimized to perform faster (hide objects you don’t need, reduce polygon count, etc.) so you can see your animation playing smoothly while you work. On the Scene tab of the Properties Editor, Blender has an interesting option, Simplify. If you enable Simplify, you’ll be able to select the maximum number of subdivisions that every object in the scene will have. In Jim’s case, the model is probably using between two and three levels of subdivision, which is fine for a final render, but the impact on a computer’s performance can be significant. With Simplify, you can turn subdivisions to 1 or 0 while you work on the animation. Just remember to put it back up before you launch a render!

You can also define a different number of subdivisions for the 3DView and for the render in the Subdivide Surface modifier’s options. While this is better for optimizing performance, sometimes it can be tedious to define subdivisions one by one and, from time to time, you may want to be able to preview the subdivided model in the 3DView; the Simplify feature is a good one for controlling all the SubSurf modifiers at once.