Preparing your own character

There are three main steps in creating an animated humanoid character from scratch: modelling, rigging and skinning.

Modelling

This is the process of creating your own humanoid mesh in a 3D modelling package - 3DSMax, Maya, Blender, etc. Although this is a whole subject in its own right, there are a few guidelines you can follow to ensure a model works well with animation in a Unity project.

Skin Mesh, textured and triangulated

Rigging

This is the process of creating a skeleton of joints to control the movements of your model.

3D packages provide a number of ways to create joints for your humanoid rig. These range from ready-made biped skeletons that you can scale to fit your mesh, right through to tools for individual bone creation and parenting to create your own bone structure. To work with Mecanim, the hips should be the root element of the bone hierarchy. A minimum of fifteen bones are required in the skeleton.

The joint/bone hierachy should follow a natural structure for the character you are creating. Given that arms and legs come in pairs, you should use a consistent convention for naming them (eg, "arm_L" for the left arm, "arm_R" for the right arm, etc). Possible structures for the hierarchy might be:-

  • HIPS - spine - chest - shoulders - arm - forearm - hand
  • HIPS - spine - chest - neck - head
  • HIPS - UpLeg - Leg - foot - toe - toe_end

Biped Skeleton, positioned in T-pose

Skinning

This is the process of attaching the mesh to the skeleton

Skinning involves binding vertices in your mesh to bones, either directly (rigid bind) or with blended influence to a number of bones (soft bind). Different software packages use different methods, eg, assigning individual vertices and painting the weighting of influence per bone onto the mesh. The initial setup is typically automated, say by finding the nearest influence or using "heatmaps". Skinning usually requires a fair amount of work and testing with animations in order to ensure satisfactory results for the skin deformation. Some general guidelines for this process include:

Interactive Skin Bind, one of many skinning methods

Page last updated: 2013-07-17