Today I want to tell you guys something about 3D character animation in our games. Most of our games are vehicle or car based, what has the advantage of not having 3D characters walking around on the screen. I call this an advantage because making games which feature 3D characters, or bone based animations takes more time and effort than games without them.
For the character rigs we use biped and / or CAT-rigs. One has several advantages over the other as well as the other way around. The character in the image below uses a biped skeleton. Each vertex of the character mesh is linked to a bone, or several bones in the skeleton. By transforming (moving and rotating) the bones in 3D space we are able to pose the character.
The animations are done by setting different poses of a character in a sequence, called keyframes. The computer figures out most of the motion between these poses, so we don't have to set every animation frame manually.
When we use 3D animated characters in our games there are usually more than just one character walking around. Think of enemies, friendly's or even maybe another player character. The skeletons ( biped or CAT) we use, have the same structure and names for all of the characters. This allows us to use all of our created animations on every 3D character in the game. A walk animation on one skeleton can work on a slightly different skeleton too. I say slightly different.. Big changes in size of the character or difference in the length of the limbs can affect the motion of the animation. So as long as all characters are roughly the same shape it is possible to use the same animations for them. This reduces the download size a lot, we don't have to export all the animations for each unique character doing so.