Lateral views of bicubic Hermite meshes LA-142 (A) and LA-412 (B). Compared to LA-142, LA-412 cannot capture the geometric detail of the left atrial appendage (LAA), in spite of more geometric degrees of freedom. The additional extraordinary vertices in LA-142 are needed to capture the geometric shape of the LAA and preserve element quality. Cartographic projections of LA-142 and LA-412 are displayed in (C) and (D). The distorted quadrilaterals in the cartographic projection (C) become regular in LA-142 (A), whereas the regular quadrilaterals in cartographic projection (D) become distorted in LA-412 (B) as they are deformed to capture the irregular shape of the LAA. Colors in (C) and (D) are used to indicate distinct topology regions. Valence 5 vertices are teal in (A) and (B), and are indicated by asterisks (*) in (C) and (D). Valence 3 vertices are red in (A) and (B), and are indicated by the symbol ⊗ in (C) and (D). Four valence 3 vertices at the tip of the LAA are indicated by the symbol ⊕ in (C). In (A) and (B), the mitral valve is shaded dark grey for visual contrast. LAA = Left atrial appendage; MVO = Mitral valve orifice; LSPV = Left superior pulmonary vein; LIPV = Left inferior pulmonary vein.