Art - Animation

Greetings ladies and gentlemen, it is my time to shine. Today I am going to talk about how I rigged and animated our main character, the processes I had to go though as well as some problems I had to solve and maybe a tip or two on how to make your life easier when rigging and animating models.

             Character Rig

            Character Rig

So first thing's first after the model is ready and we are all happy with how it looks the modeler throws it at me to make a rig for it and start animating it. To rig a model means I have to build a skeleton (Blender calls it armature) and apply a skin modifier to that mesh so that when I move the bones the mesh transforms accordingly. Some programs may have built in basic human skeletons that you can use but it is a good practice to try and make your own, because when you have to for example, make a custom rig for a model where there needs to be an arm sticking out of his head and that needs to move naturally you know how to make it happen. Creating the rig is fairly simple, I just add a single bone and then extrude and adjust the position of every other subsequent bone that I need. A word of advice though, try not to rotate bones because that can cause major problems when you apply the skin modifier to the mesh where certain parts of the mesh will twist along with the bones. In order to make the bones move naturally, for example, when I move the last bone in the arm towards the body the whole arm will move accordingly, I added an Inverse Kinematic (IK for short) constraint to those bones. And while adding the IK constraints to the bones I added a few extra bones to help me with controlling and moving the skeleton.

            Weight Painting the mesh

           Weight Painting the mesh

So now that the Skeleton is ready I needed to do one more thing before I can start animating the model (No one said that the animating process is a one click wonder). This process of pointing out how much the bones will deform certain parts of the mesh is fairly simple and some times it doesn't need a lot of work and will be perfect from the first time you apply a skin modifier to the mesh. But sometimes things go wrong and the neck bone is pulling a couple of vertices from the bottom of the feet, which is not normal. That's why I had to check every bone to make sure it doesn't affect a part of the mesh that is not supposed to. An easy way of doing this, if the model seems fine at first glance, is to grab the first bone I created (this will move most of the mesh because all of the bones are parented to it except for the control bones used to move the limbs). This way I can see how the mesh deforms and see if there are any major problems with it. The other problem that may occur is with the fingers because they are quite close together and the bones may think "Hey I am important enough to move this finger and half of the adjacent finger because I'm cool like that". The answer to this is no. So I had to make sure all of the fingers are controlled only by their respected bones. Fixing all of the issues I mentioned above is like painting a picture. The darker the colour the more the mesh will transform with the selected bone.

 Slide Animation

Slide Animation

Now that the whole tedious preparation stuff is out of the way, its time for the fun part: animating the character and making him do ridiculous stunts like sliding under a crumbling building for example. Due to the lack of funds and knowledge on how to clean up motion capture data I chose to do all of the animations the old-fashioned way, which is key frame animation. In this way of animating I have to grab a control bone, move it around and save its position and rotation, then move on to the next key frame and do the same. Repeat this several times and your animation is done. And because the game is in a cartoony style I can get away with slightly exaggerating the movement. Don't be fooled, this still means I have to make sure the arm doesn't do a 360 rotation through the chest of the character, this is not a normal thing to do after all we are still grounded in reality. Speaking of reality I don't really have to slide underneath a crumbling building everyday and that makes it a bit hard to animate something that I haven't done before, but fortunately for me there are reference materials all around me in real life and in movies, and if I can't get any other material I can just act out the movement i need and feel for myself how the limbs and my whole body moves.

Now when it comes to animating monsters and other creatures I can be a bit more creative of their movement but I will talk about this some other time.

Posted on October 23, 2015 .