interessting thread flozi, sadly all the links are dead. :/
(for the jumpkick com video/files)
Have you tried the animation without bos -> Lua conversion?
No, dont have the bos compiler installed...
I think I stop here for now.
For anyone who wants to experiment:
-importing BVH actually does work, if you also import the skeleton via "importort skeleton + anim from BVH"
This will delete your model and replace it with some empty objects. But those dots move in a way that looks like loading worked: the original animation is recognizeable compared to the preview .gif
-imo editing the Upspring\plugins\BOSExporter.lua to export LUS should be possible.
Here is my try:
http://pastebin.com/VkmJ1jYf
(direction of rotation is wrong, needs a minus sign or w/e CBA to test again. or maybe just wrong because pieces always rotate in whatever way they want.)
-The keyframe animation function of Upspring is imo too unfinished/crude to be really usefull. It also crashed sometimes and then all work ist lost. (or that is just normal upspring crashes)
So exporter has limited use...
-I did not know Upspring was so lua it!

Did not find a manual though or a way to reload scripts without restarting so yeah.
-Beware Kloot or anyone else wants to improve the animation stuff, please instead make the basic functions work better. (if there is chance of someone looking at it, i can make reports)