Particle size/scale distribution mechanisms: normal-distribution size sampling (isotropic or axis-scaled) and per-template scaling within a single mixed distribution.
particle_normal_distribution_convex/— convex cube particles sized from a normal distribution, scaled anisotropically along a single chosen axis (x, y, or z per region).particle_normal_distribution_sphere/— the baseline isotropic case: sphere radii drawn from a discretized normal distribution.particle_scaled_distribution/— spheres and a multisphere template combined in one distribution, each individually scaled viatemplate_scales.