...a lot of styles of arm animation would open up with another axis of motion added to the sim. I hear you on the legs; I also am aware that MOIDs are anything but free, so there aren't any good choices on that.

The problem with the two-joint design's pretty fundamental; if we want really convincing gorilla-type arms, arms with reversed joints, etc. it'd be nice if the weapons were moving the hand offsets but there was an elbow that we could lock if it reached a constraint and force the shoulder to rotate, instead of being limited to a very human range of motions and more importantly, distances. That said, I haven't tried to make any really crazy ape-man arms with the elbows really offset a lot yet or praying-mantis style arms, so IDK whether I can convincingly fake it or not.

IDK, I guess what I'm saying here (and please forgive me for meandering a bit, it's really late) is that one of the things about this engine is that under the hood, we're much more limited to the human / ACrab form and the forces being applied to the joints that must be defined than a lot of people, even a lot of the modders, really appreciate. That, and it's really hard to see what's up, short of writing some major Lua to draw stuff and give you input about forces and show the joint positions. I thought about doing that for people to use when developing characters; it'd be incredibly useful to merely be shown an overlay view of the skeleton while trying to get a walkpath built, for example.

I think it'd be really nice to have deeper access to Actors and be able to develop joints, constraints, etc., so that if we want to build, say, a wheeled thing, we can define the wheels as non-constrained joints attached to rotationally-constrained but not length-constrained joints with a constant recovery force (i.e., simple springs), develop a character with the full set of animations instead of having to work around the canned stuff with Lua, etc. IDK how hard it would be to make that data more accessible to Lua and push it out to a table that would serve as a template, but it'd be a big deal if it could be done, in terms of modding.

IIRC the last time I was here, people implied that we could just use the generic Actor class as the basis for that kind of thing, but I didn't find it amenable, because it's missing so much basic stuff, like being able to get into the AHuman Pie Menus, using AHuman function calls and moreover having to build the joint system and collision detection is reinventing the wheel.

There needs to be a good balance, where core stuff like GUI is still there and we can swap equipment, but do fundamental work on the joints and constraints and animations, not merely a walkpath. I think it would be really cool if we could define which Pie menu basis to use, too, so that you can have an ACrab with AHuman Pie, AHuman with ARocket Pie, etc.