Add support of hotspot thumbnail image

[Wolfshe]

The proposed modification allows to add thumbnail at each hotspot linker. The thumbnail is display when the mouse enter in the hotspot linker element.

The thumbnail image is defined in the config json file with the "thumbnail" attribute.

[mpetroff]

Unless I'm missing something, this can already be done by setting the cssClass hot spot parameter and using the :hover selector for the custom CSS class. Doing this styling using CSS is better for performance reasons, anyway.

[Wolfshe]

The proposed feature allows to load a specific thumbnail for a hotspot (like preview rendering of the scene associated to the hotspot). This implies to use the thumbnail attribute loaded in javascript to craft adapted css attribute.

This feature cannot be implement by a custom CSS class with :hover because hotspots don't share same thumbnail.

Best regards

[mpetroff]

This feature cannot be implement by a custom CSS class with :hover because hotspots don't share same thumbnail.

Yes, it can. You just give each hot spot a different CSS class.