Center of Gravity
The 3D center of gravity that is output in CSV files is calculated based on the positions of the spheres we use as a proxy of the person's geometry. This volumetric estimate includes the clothing of the person and the spheres overlap a little - so it's not exact - but the resulting estimate of the center of gravity is plausible and behaves as expected, for example, when jumping. The exact formula is:
cog = 𝝨i pi * wi
where pi is the position of the sphere and
wi = 4/3 * π * ri3