// Use this for initialization
void Start()
{
var ground = new Entity();
ground.m_inv = Mat3.Diag(0);
ground.I_inv = Mat3.Diag(0);
double d = transform.position.magnitude;
ground.Collider = new PlaneCollider(ground, new PE.Vec3(0, 1.0, 0), d);
PE.Engine.instance.AddEntity(ground);
}