Once the Merchandiser has laid the foundation for Configuration by establishing all Catalog Item Attributes and Rules, the 3D artist will use them as a guide to ensure visual representation adjusts with fidelity. On the 3D side, the approach is similar, there are Attributes and Rules.
Visual Attributes are containers used to control what kind of information is used by one or more rules. A Visual Attribute of type boolean might be useful to control the visibility of a mesh, while a Visual Attribute of type Asset -> Material is appropriate for controlling the mesh's Material. While one can assossiate any Visual Attribute Type with any Visual Rule, the appropriate choice will drastically reduce the complexity of a rule.
Item Attributes of Type: Part Reference correlate with Visual Attributes of Type: Asset
It's worth remembering that limiting Attribute values is accomplished by mapping Visual Attributes to Item Attributes and setting Item Rules on the respective record. An example of this can be seen here.