The 2D decomposer computes the same numbers a quantum compiler computes; this 3D companion shows what those numbers actually do. Set a target unitary U by axis and angle (or a preset gate) and the tool runs the identical Euler-angle (ZYZ) matrix decomposition to get real α, β, γ angles for Rz(α)·Ry(β)·Rz(γ) — then Play animates the qubit's Bloch-sphere state vector through the genuine 3-step rotation path this sequence describes: first a real rotation about the z-axis by γ, then about the y-axis by β, then z again by α. A gold marker fixed at U|0⟩ never moves; watching the animated white arrow land exactly on it, orbit-able from any camera angle, is a visual proof that the decomposition is correct, backed by the same numerical matrix-error check as the 2D version.