How in the powder toy vector fields calculated (ie, pressure, speed)?
Whether all the pixels are elements of a large array with arguments "presure", "velocity"?

I just think over the algorithm of magnetism. For this should be calculated view "magnetic field", it, seems to me, is similar to the view "pressure" (positive and negative charge). So I want to know how calculates the pressure field, for example, when you create a black hole (how bh influences on pressure field).

Oh! Thanks a lot!!!
I am not alone in my thoughts