Initial conditions: components: contravariant writes Ucont directly, each component the volume flux through its face in m^3/s. ic_gen is now only the hook for a script of your own: params.script is required, and its [expression] config, with generators/ic.gen's evaluator and config/initial_conditions/expression.cfg, is removed. In a source xi eta zeta are arc-length fractions rather than index fractions; i j k, scale, zero_tolerance and max_magnitude have no equivalent, though constraints: {scale} remains.