This tutorial will demonstrate how to rig a bird for flight and animate a quick flight cycle. But before even starting with any animation, it is important to understand how the character moves in real life, and to have an idea of what the character will do in the final animation. For instance, flight cycles are typically distinct to a species of birds, and even the different stages of flight, such as take-off, powered flight, soaring, and landing, have their own characteristics. An eagle, for example, moves in a completely different way to move to a pigeon or a sparrow. So designing the correct rig for the animation planned is critical. In this tutorial, we're focusing on simulating powered flight, so there is no need to rig the bird's wings to fold or the legs for walking.
Rigging for animation is a straightforward process, which consists of building a skeleton made up of joints or bones, binding the skeleton to the model (otherwise know as skinning), weighting the model, and setting up controls. In this case, the model will be controlled using Forward Kinematics (FK) instead of Inverse Kinematics (IK). The up and down motion of the wings will be controlled with two User Data sliders and a bit of XPresso. The sliders will greatly simplify the animation process: instead of having to move individual joints, the sliders do the hard work. Rotating controllers in the scene will control the neck and tail.