In the cases of oblique lines and slanted faces (like lateral faces of a pyramid), a uniform staircase profile is used by all of [[FDTD Module]]'s three mesh generators. in other words, the cell sizes or grid line spacing remain the same across the edge or face, since the slope is constant. In the case of curved edges and curved faces or surfaces (like a sphere), the uniform and regular mesh generators use a uniform staircase profile. However, the adaptive mesh generator uses a variable staircase profile, where the cell sizes of grid line spacing vary with the curvature (derivative) of the edge or face. As a result, a higher mesh resolution is achieved at "more curvy" areas to better capture the geometrical details.
{| style="width: 600px" border="1" cellspacing="1" cellpadding="1" align="center"|[[Image:FDTD31(1).png|400px]]|[[Image:FDTD32(2).png|400px]]|}
Figure 1: A pyramidal object with a slanted plate and its adaptive FDTD mesh.
{| style="width: 600px" border="1" cellspacing="1" cellpadding="1" align="center"|[[Image:FDTD26.png|400px]]|[[Image:FDTD25.png|400px]]|-| [[Image:FDTD27.png|400px]]|[[Image:FDTD28.png|400px]]|}
Figure 2: The geometry of a sphere and its regular and adaptive FDTD meshes (top and perspective views).
{| style="width: 600px" border="1" cellspacing="1" cellpadding="1" align="center"|[[Image:FDTD30.png|400px]]|[[Image:FDTD29.png|400px]]|}
Figure 3. The geometry of a helix curve and its adaptive FDTD mesh.