Show images in the visualiser

[rodolpheh]

The current visualiser example doesn't show how to access images and display them. This Pull Request introduces changes in the visualiser sample to show how images can be accessed and display.

Some extra efforts would be necessary to properly synchronize the drawing of the images with the drawing of the hands, but the current changes are already a good effort in this direction.

[boringwar]

Hi, @rodolpheh, could you please tell me where to find the user document for python3 interface of ultraleap.

[rodolpheh]

There isn't any as far as I'm aware, you'll have to read through the code yourself. If you need any help or have any question, contact Ultraleap's customer service.