Scientists have upgraded the DISPATCH simulation framework to couple directional stellar radiation, diffuse infrared transport, thermochemistry, sink particles, protostellar jets, and an equation of state. Short‑characteristics ray tracing calculates direct radiation while preserving source directions and shadowing, and multiple frequency bands track both ionizing and non‑ionizing light. The new simple “color M1” diffuse‑infrared solver reproduces the temperature profile of a standard DUSTY envelope to within 1 % for optical depths τ₁≤1 and within 12 % for τ₁=10, showing that the method captures the main physics of radiative heating in dense clouds. The authors note that a reduced hot‑gas cooling treatment, which omits Fe, Mg, and Si, yields instantaneous cooling times about 20 % longer than a full collisional‑ionisation‑equilibrium (CIE) model, an important caveat for studies of shocked gas.

Figure 8 demonstrates the hybrid treatment: two point sources illuminate a dense clump, producing overlapping shadows for direct radiation while diffuse re‑emission smooths the dust temperature distribution. Table 2 lists the thermochemical prescriptions that underpin the model.