This section describes how to create objects with rounded corners. The example file here was created in FDTD, but these structures can be found in the component libraries of other products as well.
Creating objects with rounded corners
Objects with rounded corners can be created with the polygon object. The simulation file usr_round_corners.fsp contains an n-sided equilateral shape with rounded corners created using the polygon primitive and then extruding. This object can also be accessed via the object library. By default, one corner of the object always points in the +X direction. The rotation tab of the structure group can be used to rotate the object.
Rounded objects can also be created using a combination of rectangles, spheres and extruded circles (tubes). Using the structure group script, the above all-rounded rectangular prism can be produced and easily modified.
Note: Continuous slope
Sometimes, adding a sphere to round a part of the structure can be tricky. The sphere must be positioned such that there is a continuous slope at the interface between it and the structure. Often, satisfying this criteria has the unwanted effect of the sphere protruding out of the sides when it shouldn't. To fix this, we use a revolved custom object with a spherical equation, rather than a sphere. This allows us to specify the domain of the equation (x-min and x-max) and thus, limit the section of the sphere that we want. The rounded cone is a good example of this problem.