This is the last post about 3D model and animation basics on avatar character. I’m going to show you the process to animate the character, a simple animation of a few seconds.
First, it is necessary to create a skeleton. The skeleton is a group of joints which simulates the human skeleton. It will be used to move the characters extremities. The process to create is simple, just using the Skeleton>Joint tool. Using the side view I clicked at the beginning of the hip, next I clicked again more or less on the same position as the knee of the character, both clicks displayed a bone. A bone is the union of two joints.
I only have to repeat the process for the entire of the body taking special care on parts such as hands and head, creating the correct topology of a human skeleton.
I just modeled a half of the skeleton because we can use Mirror Joint tool to duplicate.
Secondly, we can move the character using two different techniques, Forward Kinematics and Inverse Kinematics. The first one is a simple method which rotates the bones individually; it could be useful in some parts. Second one, Inverse Kinematics allows us to link bones creating a hierarchy between them, for example I created an IK (Inverse Kinematic) between the beginning of the leg and the ankle. That IK allowed me to move the IK handle which will be the driver of the leg bones, so I can move more than one bone with that technique with a correct hierarchy. I used IK on legs and could be useful on arms.
Once IK finished, I just associate the skeleton to the mesh, I select first the skeleton, then I select the mesh and by clicking on Skin>Bind Skin>Rigid Bind I obtain the skeleton unified with the character.
After that I changed some attributes on bones to block impossible movements on arms and legs, for example the arm will never use the Scale X attribute so I clicked with the right button and clicked on Lock and Hide Selected. I repeat that on every attribute I consider that won’t be useful.
Next, in order to prevent rare movements or deformations on legs I created a pair of Locator. That control allowed me to fix the orientation of the knees to those points as we can see on next picture. It is so useful to avoid rare effects when we are moving legs and character mesh. To associate the locater to the IK handle just click the locator and then select the IK too, click on Constrait>Pole Vector and both control will be linked.
Last thing I did with the skeleton was to ensure that bones were associated with the correct surfaces of the mesh. By clicking on a bone and then on Edit Deformers>Edit Membership Toll Maya will display points in yellow colored which represent the point associated to the bone. Points not associated points that will not move.
Now, I could move any extremity of the character and simulate human actions. Next phase was to create the animation.
For that purpose I just set 220 frames on Time Slider and changed the frames per second to 60, that values results in a 3.6 seconds of animation. Short duration but enough for get the concepts of animation.
The animation consists on the character running and jumping the fence. I was moving the IK handles, bones rotation, moving the player around the environment and clicking on “S” key to save the position of each control modified. After some hours I finished that simple animation.
Here you can download the Maya project: Avatar