General Principles

The Assets Tool has two main buttons in each of its tabs: + and -. The behavior of these buttons depends on the selected item in the tree view that lies besides them. The + button adds a new item to the current selection and the - button removes the current selection.

 

Structure of a Character

A character in the Assets Tool can be represented as a tree having the following structure: 
+ Character
 | +--+ Geometry Group
 | +--+ Assets Group
         | +--+ Mesh Asset
                 | +--+ Mesh - Shader
A character can contain several groups. A valid character must have at least one group. Each group can contain several mesh assets. A valid group must have at least one mesh asset. A mesh asset can contain several meshes. These meshes represent the actual meshes from Maya or the FBX file.
 
See below a definition of each part of the structure, and Creating Assets Group for a practical example.
 

Geometry Group

A Geometry Group represents a set of base Geometry files (.fbx files), such as a FBX file describing the bind pose of the character. When exporting a "Selection as FBX" from the Asset Manager, either the currently selected Geometry file is replaced, or (if nothing is selected) a new Geometry file is added to the Geometry Group.
 

Assets Group

An Assets Group represents a choice in the distribution of mesh assets. When a group contains more than one mesh asset, this means that one mesh asset will be chosen among them. A group with only one mesh asset guarantees that the meshes in that mesh asset will be present on the character (when exporting the characters of a CrowdField to FBX files or when rendering them using a renderer plugin). If a group contains the empty mesh asset, this means that the character has a chance to have no mesh among the meshes in that group. 
Think about an army with swordsmen and bowmen. You could create an asset group "Weapon" which would contain two mesh assets: "sword" or "bow".
 

Mesh Assets

A Mesh Asset is a part of the geometry of a Crowd entity. It contains one or more meshes that are treated as a whole. The role of a mesh asset is to guarantee that all the meshes it contains belong together and will either all be present on the character or absent from the character when exporting the characters of a CrowdField to FBX files or when rendering them using a renderer plugin. There is a special Mesh asset called the empty asset which doesn't contain any mesh. It can be used to represent the absence of a mesh in an asset group.
Still thinking about an army with swordsmen and bowmen, the mesh assets "sword" would contain a sword and its scabbard and the mesh assets "bow" would contain a bow and its quiver filled of arrows.
 

Meshes

A Mesh directly represents the mesh from Maya or the FBX file that is associated to the character. When the Maya scene or the FBX character contains more than one mesh with the same name, these meshes are displayed with their full path in the scene, using the | (pipe) separator (for example |Grandparent|Parent|Mesh). Each mesh can have one or more shaders.
 

Shaders

Shaders correspond to the name of the shaders applied to the rendered geometry