Notes about the RIG file extension:
Incorrect file associations could be the result of underlying issues within your PC system. As such it is highly recommended to scan your PC for invalid registry entries, unused processes and other unfavourable system settings to identify slowdown issues.
The RIG file type is primarily associated with 'LightWave 3D' by NewTek. LightWave offers modeling, animation, dynamics, volumetric rendering, particle effects and a motion picture quality rendering engine with unlimited render nodes. 3D character RIG file for transfering bones and IK setups to and from other characters. Introduced in Ver. 8.