OFP/ARMA family uses parabolas. You need just 2 measurements at 2 time points to calculate a hit. This is also perfectly suited for calculation with SSE in less than a kilocycle.
They also do deflections when you're firing at, e.g., a thin wooden wall a bullet can go through or something hard hit at a shallow angle causing a ricochet.
UE does bruteforce calculation as I know.