A data storage and retrieval system for a computer memory comprising: a viscoelasticity map that associates viscoelasticity values (V EK, V E1 -V E4) with three-dimensional, 3D, locations; a volume mesh structure (118, 234, 932) that represent a 3D model that includes volumetric cells (V C1) that include surface vertices (P0-P15) that correspond to 3D locations that are associated with viscoelasticity (V EK, V E1 -V E4) values by the viscoelasticity map and include internal vertices (Q0-Q15) that correspond to 3D locations that are associated with viscoelasticity values (V EK, V E1 -V E4) by the viscoelasticity map; sorting means for sorting the surface vertices (P0-P15) and internal vertices (Q0-Q15) of the volume mesh structure (118, 234, 932) to configure said memory according to a unified mesh structure that associates volumetric cell vertices with viscoelasticity values (V EK, V E1 -V E4), said unified mesh structure including: a first list within a unified list, the first list including the 3D locations of the surface vertices (P0-P15) of the volume mesh structure; and a second list following the first list within the unified list, the second list including the 3D locations of the internal vertices (Q0-Q15) of the volume mesh structure, and wherein to access the first list and second list within the unified list, a same base address to the unified list and at least a count of surface vertices is used when simulating deformation and rendering colour or texture. a viscoelasticity map that associates viscoelasticity values (V EK, V E1 -V E4) with three-dimensional, 3D, locations; a volume mesh structure (118, 234, 932) that represent a 3D model that includes volumetric cells (V C1) that include surface vertices (P0-P15) that correspond to 3D locations that are associated with viscoelasticity (V EK, V E1 -V E4) values by the viscoelasticity map and include internal vertices (Q0-Q15) that correspond to 3D locations that are associated with viscoelasticity values (V EK, V E1 -V E4) by the viscoelasticity map; sorting means for sorting the surface vertices (P0-P15) and internal vertices (Q0-Q15) of the volume mesh structure (118, 234, 932) to configure said memory according to a unified mesh structure that associates volumetric cell vertices with viscoelasticity values (V EK, V E1 -V E4), said unified mesh structure including: a first list within a unified list, the first list including the 3D locations of the surface vertices (P0-P15) of the volume mesh structure; and a second list following the first list within the unified list, the second list including the 3D locations of the internal vertices (Q0-Q15) of the volume mesh structure, and wherein to access the first list and second list within the unified list, a same base address to the unified list and at least a count of surface vertices is used when simulating deformation and rendering colour or texture. a first list within a unified list, the first list including the 3D locations of the surface vertices (P0-P15) of the volume mesh structure; and a second list following the first list within the unified list, the second list including the 3D locations of the internal vertices (Q0-Q15) of the volume mesh structure, and wherein to access the first list and second list within the unified list, a same base address to the unified list and at least a count of surface vertices is used when simulating deformation and rendering colour or texture.