BT Card

This card defines a mesh of surface triangles in the shape of a flat triangle.

On the Construct tab, in the Surfaces group, click the  Triangle (BT) icon.

Note: For creating planar surface meshes, in general the PM card would be preferred over the BT card.


Figure 1. The BT - Specify a triangle dialog.

Parameters:

S1, S2, S3
The points S1 to S3 are the three corner points of the triangle. These points should have been defined previously with the DP card.
Specify non-uniform meshing
Usually a triangle is meshed according to the edge length specified with the IP card. It may be required to use a finer mesh size in a particular direction. Check this item if finer meshing is required along any edge. The mesh sizes are in metres and are scaled by the SF card.
Mesh size along side b:
The mesh size along edge S2–S3.
Mesh size along side c:
The mesh size along edge S3–S1.
Mesh size along side a:
The mesh size along edge S1–S2.
The direction of the normal vector ( n ^ ) of the subdivided triangles is determined by the right hand rule through all the corners. This direction is only important when used with the physical optics (PO card) or with dielectrics (ME card) or for the CFIE (CF card).

Examples of BT card usage

The mesh shown below was created with a BT card using uniform meshing.



Figure 2. Example of a uniform mesh in the shape of a triangle created with the BT card.
The mesh shown below was created with a BT card using non-uniform meshing.


Figure 3. Example of a non-uniform mesh in the shape of a triangle created with the BT card.