The Hidden Blade Assassin's Creed in Depth

Original video:
http://thehiddenblade.com/ghost-paris-glitch-aka-ultrablending

So I accidentally stumbled on a different way to activate ultrablend. Some types of environmental blend can be used for this.

Originally it was discovered when I fired the guillotine gun right before attempting to get on a bench, which led to the bench sitters getting spooked, preventing Arno from sitting. You can also use the phantom blade or poison darts. Tools can't be used near environmental blend spots.

Further tests showed for some benches the timing is tighter, only working when you are starting to get on. It also works for the characters leaning against walls, but not so far for the carriage repairing NPCs (another type of environmental blend).