Visualization of SO(3) sampling grids using the axis-angle representation. The color represents the magnitude ϑ of the rotation (from blue to red). (a) Regular sampling of Euler angles (as in Eq. (9)) with B = 4, leading to (2B)³ = 512 samples; (b) Uniform distribution using Halton sequences [74] with 512 sampling points; (c) Uniform incremental sampling using the Hopf fibration [72] with 576 sampling points.