Three.js - technique for turning a transparent PNG into a 3D “card” with the geometry of the transparency

问题

The goal is to turn any transparent PNG into a 3D card with a slight thickness and the geometry of the image minus transparency. For example, I'd like to take an image like this one: http://findicons.com/files/icons/730/soft/128/user_male.png and turn it into a card object with a slight thickness. However, the card should not be rectangular - its edges should follow the shape of the transparency in the image.

Is there any simple procedural way to accomplish this on any given PNG?

Thanks.

来源：https://stackoverflow.com/questions/23439339/three-js-technique-for-turning-a-transparent-png-into-a-3d-card-with-the-geo