joinPoly
Joins given polygons into one polygon. The given polygons should all be touching
each other at their end points so that they have the appearance of on polygon already.
After the join it wont look like anything has happened, but now the selection has
become one object. This function creates a composite object that keeps the input
polygons as its children. If the children are changed the join will be re-computed,
so there is no need to get the input perfect before doing the join. There is a
tolerance field in the join object that says how close end points need to be to
be considered joined. Each polygon is joined on each side to the polygon that
has an end point that is the closest of the set of polygons, so it is pretty safe
to make the tolerance very large. The only possible bad effect of this is that
result might become closed unintentionally. The order of selection does not
matter. If the coellese joins check box is checked, a join made with
another join in the selection will result in a bigger join instead of a join of joins,
which can be confusing if your going to work at the database level.
polygons :
ObjectSet
Polygons to join