Evolution of grain shapes for a-C BA (red), BAM1 (green), and BAM2 (blue) grains with an effective radius of a_eff = 200 nm (left panel), a_eff = 350 nm (middle panel), and a_eff = 500 nm (right panel), respectively. Dots represent the initial grain shape i.e., ω_agg/ω_disr = 0 whereas crosses are the grain shape at disruption for ω_agg/ω_disr = 1. We note the clear tendency of the porous grains to become oblate in shape with increasing ω_agg.