Hi
I take it that this is the problem that prevents the full use of MH in games?
Example: you can't assign a uniform animation to multiple different characters (in games like The Sims)?
Yes and no. You have to keep the characters a little uniform then. The problem with the root bone is ugly and it could be fixed. Thomas Larrson's diffeomorphic retargeter can recalculate one bone through one animation. Game engines then calculate the height of the character so it always touches the ground.
I cloned it to my repository, updated the code (Thomas is on bitbucket, but has an old version in github) ... updated it to the latest version (some time ago) and added default-poses for our skeleton. I can load bvh files now and use this as a base for our skeleton. Maybe it helps.
https://github.com/black-punkduck/retarget-bvhI only examined OpenSim and wrote an article here:
http://www.makehumancommunity.org/forum/viewtopic.php?t=16927OpenSim tends to use predefined sizes in my opinion. I accidentally upload the female proxy and it created o-shaped legs, too many vertices in crotch area.
If you check Avastar, they seem to use certain character defaults. At least when you compare the blonde character (with the wings), they look different in proportions between blender and OpenSIM.
Using the same animation: you should also think about different arm lengths etc. They will simply intersect with body parts in certain positions like crossing the arms in front of the body or in the demo appended she would scratch her face with longer arms, Sitting on the floor looked like an accident with the blonde character in OpenSim
Rig MH is probably great for individual work, but for mass animation production it is better to have as few bones as possible.
Not only bones, vertices also. The less geometry has to be created, the faster the game is. Yes bones cannot be replaced by additional level of details (LODs), this only works for vertices.
As always it is a problem to keep it detailed and realistic but also use only a low amount of geometry and memory. The reason for the use of normal maps and 100s of other tricks ...
Depending to your animation: Some of the bones are simply designed different. The upperleg02, lowerleg02 and upperarm02, lowerarm02 bones are mostly used for twisting only (rotation in local y direction).
Just an example what I am really not happy about: Shoulder rotation in reality is a rotation + movement ... and it is hard to animate that correctly ... a typical fashion pose (arms behind head) often looks ugly.
https://www.youtube.com/watch?v=LF7oST34r4sThe Sims/OpenSim are limited to the game-engine or Bento skeleton. Unity I have no experience.
Unreal engine works with our own skeleton as well. They accept it as an fbx with all we have ... and for a game? ... well it depends what you want to create: for a multiplayer environment it is certainly the best to reduce the skeleton.
For a world with 2 or 3 characters it looks different. Both worlds exist. More common is: people want to use ready made animations from e.g. Mixamo and this demands a special skeleton ....
At the moment I only tested one of my characters in UE. A default-no toes skeleton with breast bones "uncoupled" to allow some jiggle.
I did all animations myself, partly derived from natural walks. Just for information: for UE the character walks in place normally (depending on the player-type) ... it is pushed forward a specific distance with the game controller. My movement was two steps and I wrote a blender plugin to place the root bone (it is NOT fixed) around a center point to allow hip movement.
It uses the face bones to speak, phonemes I figured out with papagayo ... (no sound added because I "stole" her voice, sorry), this was created with an animation overload starting from the neck bone, I can zoom to her face, so detailed bones are needed.
But I don't know why she needs ten tongue bones ... (well in reality there might be a reason so
) ... so yes my skeleton will have less bones in some areas but especially the bones for volume (buttocks when sitting, belly when bending forward) will be added but then also be animated with constraints ... deform versus pose bones ...
By the way: if you prefer shape-keys for the face: a shape-key is a duplication of the character in memory, that is not necessarily better when you have a lot of characters. Nevertheless they work in UE and they can also be bound to a bone.