3D volumetric renderings of the shocked circumstellar shell (green, first two columns) and ejecta distributions (red, right column). The green renderings in the first two columns show results from models W15-IIb-sh-HD+dec-hr (top row) and W15-IIb-sh-MHD+dec-rl-hr (bottom row) at two evolutionary stages: approximately 100 years before the current age of Cas A (left column) and at the present age of Cas A (center column). The red volumetric rendering in the rightmost column illustrates the corresponding ejecta distributions at the present age of Cas A.