Geometry Setup Tips Using Ansys Lumerical DGTD — Lesson 2

Partitioned Volume Mode

The partitioned volume mode can generate a partitioned volume of the simulation region composed of different domains and surfaces and represents exactly what a solver can see during simulation. This feature can be used to make sure that the geometry setup of your simulation is exactly what you intended it to be in terms of the location of simulation objects, sizes and dimensions, assigned materials, and so on.


Reference Geometries

Reference geometries can be used to assign various simulation objects such as boundary conditions, sources, and monitors to any desired volume or surface in the simulation. This gives you the freedom to apply attributes to arbitrary geometries. The following video will walk you through the concept of reference geometries, their different types, and their applications. Reference geometries are a general feature available in the finite-element IDE, not just the DGTD solver.


Mesh Order

Mesh order is used by the simulation engine to select which material to use when two materials overlap in parts of the simulation region. This will avoid confusion when there are two materials assigned to a part of the simulation region by giving one higher priority than the other.


Preserve Surfaces

The preserve surfaces option allows you to preserve the surfaces (interfaces) that belong to a geometric object regardless of the mesh order when there is overlap between various geometric objects. You can create separate domains in the simulation even though the material assigned to those domains is the same.



There can be a need to form a complex geometry by merging multiple geometries. In this video lesson, we will demonstrate how geometries can be merged by disabling the “preserve surface” option.


Open Simulation Boundaries

By default, the extent of the simulation is determined by the simulation boundaries. In this video lesson, you will learn how to define the simulation region based on geometry.