Converts a regular mesh defined by X,Y and Z into a regular triangulation. The output is patch data (triangles) in the faces “F” and vertices “V” format. The quadrilateral mesh faces are converted to triangles by splitting the faces into triangles according to the setting tri_type:
tri_type ='f' -> forward slash division of quadrilateral
tri_type ='b' -> back slash division of quadrilateral
tri_type ='x' -> Cross division of quadrilateral
The output coordinates "V" are in the form of V=[X(:),Y(:),Z(:)];
For forward and back slash subdivision no extra coordinates are introduced and therefore the original meshgrid formatted coordinates can still be used for plotting, see examples below. For cross division extra points are created at the centre of each quadrilateral face using the mean of the input coordinates. The extra coordinates are the last prod(size(X)-1) points (e.g. V((numel(X)+1):end,:) ) and can therefore be replaced by interpolated coordinates if desired, see example.
Fix of face order
Updated the vertex order for the triangles so that they are compatible with functions such as PDEGRAD