/*! \page aspect_ratio_3d_page Aspect ratio 3D \n The <b>Aspect Ratio 3D</b> mesh quality criterion calculates the same parameter as the \ref aspect_ratio_page "Aspect ratio" criterion, but it is applied to 3D mesh elements: tetrahedrons, pentahedrons, hexahedrons, etc. - The <b>Aspect Ratio</b> of a \b tetrahedron 3D element is calculated by the formula: \image html formula1.png - Other element types like polyhedron, pentahedron and hexahedron use the following formula: \image html formula2.png <em>To apply the Aspect Ratio 3D quality criterion to your mesh:</em> <ol> <li>Display your mesh in the viewer.</li> <li>Choose <b>Controls > Aspect Ratio 3D</b> or click <em>"Aspect Ratio 3D"</em> button of the toolbar. \image html image144.gif <center><em>"Aspect Ratio 3D" button</em></center> Your mesh will be displayed in the viewer with its elements colored according to the applied mesh quality control criterion: \image html image86.jpg </li> </ol> <br><b>See Also</b> a sample TUI Script of a \ref tui_aspect_ratio_3d "Aspect Ratio 3D quality control" operation. */