This changes how/whether padstacks connect to any rectangle or polygon on the current layer. The first argument can specify one object, or all selected padstacks. The second argument specifies the style of connection.

Thermal styles:

0 no connection,
1 45 degree fingers with sharp edges,
2 horizontal & vertical fingers with sharp edges,
3 solid connection,
4 45 degree fingers with rounded corners,
5 horizontal & vertical fingers with rounded corners.

Padstacks may have thermals whether or not there is a polygon available to connect with. However, they will have no visible effect until a polygon is drawn around the padstack.