Left: Users can start from scratch for non-standard creatures, or generate a generic biped as a base.
Middle: Individual rig parts, any combination of which can be connected and will work together.
Right: Some tools included with eRig to make rigging and skinning easier.
eRig allows non-technical students to create simple rigs for their models, including:
- Arbitrary rig-component configurations
- Ik/Fk switches on arms and legs
- Reverse foot rig for Ik legs
- Optional proxy-geometry generation
- 2-skeleton system for easy exportation to games
eRig can be downloaded here, and supplemental files are available here.
As a senior at WPI, I noticed that there was almost no rigging in the school's curriculum, and yet students were still expected to make high-quality animated models for their games. In addition to pushing my department to incorporate rigging instruction into classes, I proposed an independent study geared toward developing a simple generic rigging tool (eRig) that students could use without knowing anything about rigging. This project culminated in a one evening workshop devoted to showing students the basic concepts, as well as several hours of instructional video showing these concepts and how to use eRig. The tool and materials were well received, and animation professors have since provided them to several courses.
eRig is designed around several base rig components (spine, leg, arm, head, etc). Each of these components has its own custom setup functionality, and can be attached to any other component, allowing rigs to be created for abnormal creatures. The prototype of the tool uses standard Maya joints as placement markers for the components. The user places these joints as desired, and then presses a button in the eRig window. This causes eRig to walk down the joint hierarchy, building the rig based on the components it finds. The rigs generated feature standard functionality such as Ik/Fk switches (with pinning), reverse foot rigs, and proxy-mesh generation. For most student projects at WPI, these features provide more than enough animation freedom without being overly complex.
As the IMGD major is primarily gaming focused, it was important that animations be easy to export to game engines. eRig generates a second copy of the skeleton that is then constrained to the skeleton with the control rig. Users bind to the constrained skeleton, allowing them to bake down all rigged animation to simple FK and delete the rig, providing clean files for exporting to games.