What are the best practices for rigging a character in game engines?

2 Apply skinning and weight painting

Skinning is the process of binding your mesh to your skeleton, so that it follows the movement and deformation of the joints and bones. Weight painting is the process of assigning weights to each vertex of your mesh, to determine how much it is influenced by each joint or bone. To ensure successful application of skinning and weight painting, there are some best practices to follow. For example, you should use a skinning method that suits your character and game engine, such as smooth or rigid skinning, or a combination of both. Additionally, you should start with a basic skinning, such as automatic or envelope skinning, and then refine it manually by adjusting the weights of each vertex or region. Furthermore, you can use weight painting tools that allow you to paint weights interactively on your mesh with different brushes, modes, and settings. You can also use weight mirroring tools to copy the weights from one side of your character to the other, and use weight locking tools to lock the weights of certain vertices or regions. Finally, it's important to test your skinning by animating your skeleton and checking for any errors or unwanted deformations.

3 Use blend shapes and drivers

Blend shapes and drivers are useful techniques to add more detail and expression to your character rig, as they allow you to create different shapes or forms of your mesh, and control them with attributes or controllers. For example, you can use blend shapes and drivers to create facial expressions, muscle bulges, or morph targets. To use blend shapes and drivers effectively, it's important to follow some best practices. You should use a consistent naming convention for your blend shapes and drivers, and group them logically by categories or functions. You can also use a blend shape editor or a similar tool to create and manage your blend shapes, setting the weights and influences of each shape. Drivers can be used to link your blend shapes to attributes or controllers such as joints, bones, curves, or sliders. Additionally, expressions or scripts can be used to create custom logic or behavior for your drivers such as conditional statements, mathematical operations, or randomization. Finally, it's important to test your blend shapes and drivers by manipulating the attributes or controllers and checking for any errors or unwanted deformations.

4 Optimize your rig for performance and compatibility

Optimizing your rig for performance and compatibility is an essential step to guarantee that your character rig functions without issue in your game engine and does not cause any problems or conflicts with other assets or systems. To achieve this, you should delete or hide any unnecessary elements from your rig, such as extra joints, bones, shapes, or controllers, and clean up your scene and history. Additionally, you should bake or export your rig to a compatible format for your game engine, such as FBX, OBJ, or GLTF. Also, test the rig in the game engine and check for any errors or issues with the skeleton, skinning, blend shapes, or drivers to fix them accordingly. Lastly, optimize the rig for different platforms and devices such as PC, console, mobile, or VR; while adjusting the level of detail, resolution, or complexity of the rig according to the specifications and limitations of each platform or device.