I need a game engine that supports force fields in 2d or 3d, but suitable for 2d calculations, like bullet.
Each body I want to simulate is represented as a set of points. Each point has positive mass and can accept force. Force field is updated every tick. Engine should accept force applied to every point and return point speed values and coordinates. Each body made of particles should move as a whole thing in result, relative position of particles must persist, hence this is a rigid body. If engine does not support setting body as a set of points it should allow setting density function, or some other means to let have non-uniform density.
Is there any that can do that, preferably cross-platform.