About the Envelope Creator
The traditional method of creating envelope deformations is to create it point by point. However, since envelopes are often used to deform drawings and shapes around their outlines, having to create envelope deformation chains by tracing their outline with the Rigging tool may be redundant.
Using the Envelope Creator, you can automatically generate a deformation chain that either wraps around the outlines of your artwork, or goes right through its shape. This can help you quickly generate envelope or curve deformation chains based on your artwork.
Before making the Envelope Creator generate an envelope, you can configure the amount of points it should create on the deformation chain as well as how those points will be distributed along the shape. If the results of the Envelope Creator are not satisfactory, you can try tweaking the parameters and make it generate a new envelope, and repeat the procedure until you get the best deformation chain possible.