Joint objects are used to join two physics bodies together . For a much detailed explanation about joints, check these pages from Solar2D API

Before selection the Set joint properties option, make sure you select a layer already set as a body. Doing so, it will open the following window:

Properties panel:

Information about the current layer content will appear in the top of the window (position and size). It is important to understand that animations will always use the current position of the layer, group or page as starting point.

Optional parameters

these parameters may not work for all joint types. However, some of them are mandatory for some joint types. For a detailed explanation of each field, check