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 | horizontal & vertical fingers with round edges,
2 | horizontal & vertical fingers with sharp edges,
3 | solid connection,
4 | invalid, do not use
5 | 45 degree fingers with rounded corners.
6 | 45 degree fingers with sharp edges,
noshape | remove copper shape on layer

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.