Unexpected default behavior for Body

[MartinSStewart]

I created a physics simulation and ran it but it appeared to be frozen. I lost a few minutes before realizing that bodies default to the static behavior. Maybe it would make more sense if defining a body always requires you to explicitly choose a behavior instead?

[w0rm]

@MartinSStewart I like this suggestion! It is more in line with the elm-3d-scene and elm-geometry API. Also it seems easier to calculate everything during the construction because the total mass is known. Do you think that we need to be able to change the mass after the body is created?

I actually think that @ianmackenzie already suggested this to me before. Will definitely consider for the next major release.

[MartinSStewart]

I guess there might be use cases where the mass can change. Perhaps a "ground pound" move in a physics based fighting game would involve increasing the mass of a body before it hits the ground. Or something like Katamari where a sphere accumulates mass as it rolls over other physics objects.