Just thought I’d post some videos.
It looks like you could simulate muscles by having a muscle mesh in the compressed state. Then attach bones to the ends and stretch it into position when the game starts. All the muscles above are part of a single soft body. I’m not an artist so the anatomy is probably all wrong.
I think the soft bodies are just meshes attached to Flex particles. It might be possible to wait for the muscles to stretch to the default pose and then run the particle / mesh linking code. Then the original troll mesh could be skinned to the muscles. It might even be ok to delete the original muscle meshes (only need the Flex particles). I’m not really sure how to do this so I’d appreciate any suggestions.
I might try adding some bones to key points on the surface of the mesh e.g biceps. Then I could use the vertex index to bake the surface bones to the muscle animation. This means Flex could be used to create more realistic characters and the converted bone animation could be used in a game that doesn’t support Flex.