Fast math¶
Approximations and intrinsics-backed paths in Runtime/FastMath/ for hot loops.
Examples¶
using static Unity.Mathematics.mathx;
float invLen = x.fsqrt(); // fast inverse sqrt style path
float r = x.fastrp(); // fast reciprocal (where applicable)
float s = x.fastsine(); // sine approximation
float a = y.fastatan2(x); // fast atan2
Accuracy¶
FastMathAccuracyTests.cs compares fast paths against Unity.Mathematics reference implementations within configured tolerances.
Know your error budget
Use fast variants in inner loops (particles, mesh deform, audio DSP). For critical precision (finance, long integrators), prefer math.* reference functions.
Burst¶
Many fast paths use Burst intrinsics (Unity.Burst.Intrinsics) where SIMD helps.