I suggest adding this as a core scene node, as there have been many requests for this. It can be used for (e.g.) aligned decals like trees, or for 3D line (beam or bolt) effects.
Three types of facing are provided: opposite camera, facing camera from centre point, facing camera from end points. The last mode enables fairly seamless chains of billboards which can be used to build a 'trail' effect (e.g. like in Homeworld) without using cross-polygons or other solid objects.
Texture translation is provided, allowing textures to be "flowed" along billboards.
Sample app 12, terrain, has been modified to demonstrate the use of aligned billboards. The black pylons look scrappy, but they are just there to demonstrate the functionality. The beams are a bit nicer.
Comments, suggestions, bug reports are very welcome. Building and testing on non-Windows platforms would be very useful.
Sample screenshot:
