The split method enumerations are used to determine what criteria is used when the TIN creation algorithm decides whether or not to split a triangle.
This specifies that the inscribed radius will determine whether or not a specific triangle will be split while creating a TIN.
Inscribed radius refers to the method of drawing the largest circle you can within a triangle. The radius of this circle is compared to a given minimum radius allowed. If the radius of the inscribed circle is less than the given minimum radius, then the triangle will not be split.
This specifies that the angle deviation will determine whether or not a specific triangle will be split while creating a TIN.
The angle deviation method refers to comparing the angles in a triangle to a given value in degrees of the smallest allowable angle in the TIN. When a triangle is tested to see if it should be split, each of the three angles in the triangle is compared with the given smallest allowed angle. If any of these angles is smaller than the smallest allowed angle, the triangle will not be split.