We consider a class of stochastic reaction-diffusion equations on the three dimensional torus. The non-linearities are odd polynomials in the weakly non-linear regime, and the smoothing mechanisms are very general higher order perturbations of the Laplacian. The randomness is the space-time white noise without regularisation. We show that these processes converge to the dynamical $Φ^4_3 (λ)$ model, where the coupling constant $λ$ has an explicit expression involving non-trivial interactions between all details of the smoothing mechanism and the non-linearity.