Almost rectangular triangulations

Triangulating quadrilaterals. A method includes accessing an irregular grid comprising a plurality of irregular quadrilaterals. A determination is made that each of the irregular quadrilaterals in the irregular grid is not a concave and is a convex quadrilateral. On a grid basis and as a result of determining that each of the irregular quadrilaterals in the irregular grid is not a concave and is a convex quadrilateral, each of the irregular quadrilaterals in the irregular grid is triangulated to create a triangular mesh by defining diagonals from at least one vertex point of each of the irregular quadrilaterals in the irregular grid to the diagonally opposed vertex point of the same irregular quadrilateral. The triangular mesh is stored in a computer readable storage medium that can be accessed by an application for performing tasks related to data visualization, computer graphics, computational geometry, etc.