A zero-cost animation production workflow. This is FAIRLY EXPERIMENTAL, please do update if possible!
Animation production for Sine Space has been a bit of a neglected topic. Here is a fresh end-to-end process and toolchain for getting animations/poses together for your furniture, vehicles, and etc.
1. QAvimator ()
This older opensource application does one thing and one thing only, and does it fairly well. It allows you to pose an avatar model for keyframes on a timeline, and output the resulting humanoid animation as both a proprietary file and as a mocap motion file (BVH). Version 0.1.1.426 on Windows 10 is being used in this workflow.
We wont get into how to use QAvimator; it is simple, and if you've ever made a paper flipbook and used a computer, you should not have a problem working out how to use QAvimator. One note though regarding storage: It'll try and save to the directory in 'Programs (x86)' where the executable lives. That's bad. That way lies madness. Make a data directory somewhere and use it.
2. Blender ()
Blender is exactly the opposite of QAvimator in scope; it does *everything*. Including provide for the production of animations. However, blender is a highly complex tool with a steep learning curve and a user interface made by aliens from alpha centauri, so we will use it only for converting from BVH to FBX. Blender version 2.78 is being used in this workflow. Doing so is fairly straightforward: Click 'File->Import->Motion Capture(.BVH)'. You should not need to tweak any settings here; just import it according to the defaults. Next, export it as FBX (File->Export->FBX(.fbx)).
If you've never used blender, pay careful attention to the file saving dialog, it's a bit different. I'd recommend fiddling with it a bit and gathering some confidence that my files were being saved.
Finally, we're getting the animation into Space. This is where the important tweaks come into play. The process is not unlike that of importing any other FBX, excpet for a few notable ddifferences.
First, you'll want to click 'Assets->Import Asset...'. This will take you into the file selector dialog; browse to your data directory (you did make one and use it, yes?) and select the FBX version of your animation saved from blender in the previous step.
Your FBX is imported now, but there are various tweaks that need be applied to get it into a proper working state for Space. First, click the 'Rig' tab on the import properties pane. Set the anim type as 'Humanoid'. Click apply. On the 'Model' tab, untick 'Use File Scale'. Click the Apply button. You should be set; there will be a folder generated in your unity project's assets named after the file you imported. Within that will be the clip(s) (animations). These should be ready to use in your vehicle furniture sits or animation controllers in Space.
Good luck and happy animating! ANIMATE ALL THE THINGS!!