Frequent errors when solving constraints/contacts using Lagrange multipliers

[hugtalbot]

When users wish to solve their constraints/contacts problem using Lagrange multipliers, they usually make some mistakes.
Here is a list of them so that one may avoid them in the future 🚀

• Make sure to use a FreeMotionAnimationLoop
• Make sure to have a ConstraintSolver (GenericConstraintSolver or LCPConstraintSolver, optimized for contact-only) and define their convergence criteria (maxIterations, tolerance)
• For each object, make sure to define some ConstraintCorrection so that the constraints/contacts can be taken into account to correct the motion (else your object might not move at all!). Be aware of the differences between various ConstraintCorrections
• Set up carefully the detection parameters (in LocalMinDistance or MinProximityIntersection)

Hope this will help