All equations to be solved
The number of solver iterations determines quality of the constraints in the world. The more iterations, the more correct simulation. More iterations need more computations though. If you have a large gravity force in your world, you will need more iterations.
When tolerance is reached, the system is assumed to be converged.
Add an equation
Add all equations
Remove an equation
Solve
number of iterations performed
Constraint equation Gauss-Seidel solver.
The spook parameters should be specified for each constraint, not globally.
https://www8.cs.umu.se/kurser/5DV058/VT09/lectures/spooknotes.pdf