Traditional numerical analyses of laser beam transmission through “active” nonlinear materials have involved many assumptions that narrow their general applicability. As more complex optical phenomena are widely employed in research and industry, it is necessary to expand the use of numerical simulation methods. Historically, laser-matter interactions have involved calculations of “classical” wave propagation by Maxwell’s equations and photon absorption through rate equations using numerous approximations. We describe a novel numerical modeling framework that adapts itself for simulation of different types of active materials provided by a simple graphical input. Our framework combines classical electric field propagation with “active” photon absorption kinetics using computational active photonic building blocks (APBB). It allows investigating a plane electromagnetic wave propagating through generic organic or inorganic photoactive materials; while, “active” photo-transitions are implemented using the APBB algorithm on the user interface. To date we have used the method in multiphoton absorbers, upconversion, semiconductor quantum dots, rare earth ions, organic chromophores, singlet oxygen formation, energy transfer, and optically-induced chemical reactions. We will demonstrate the method with applications of amplification in rare-earth ions and multiple two-photon absorbers materials in tandem.