I grabbed it with my hands in mid-air, swung under it and subsequently let go to throw myself to the other side.
In technical terms, I jumped into an invisible gravity well which had its gravity directed upwards so it kinda looked like I swung. The drawback is a) players can't swing back and forth without leaving the pole and b) if they jump short they get thrown against the pole and then they fall down. Solution: don't jump short...
The fences that can be jumped over work in a similar way. They have low-grav volumes around them but only exactly where the player should ascend in his jump over. This is a lot better than a jumppad as a jumppad would always throw you over whereas this solution a) requires you to press "jump" like in Mirror's Edge and b) requires you to time your jump! If you jump too early or too late you aren't in the low-grav volume long enough so you don't go high enough and you jump against the fence.
Some gaps that look like they could be jumped over in Mirror's Edge have slight low-grav volumes that allow players to jump a bit farther than in KF. One example from the video is when I leave the building and jump onto the protruding ventilation-shaft.
The ziplines (aren't seen in use in the video) also work with gravity volumes. Over the visible string there is an invisible ceiling with an inwards-curved buttom. Under it is a volume that directs gravity upwards. When he uses the zipline the player is mushed into the curved ceiling instead of falling down (so he can't move left or right), and forwards, so the player moves along the zipline. It looks just about perfect if you jump into it right. Unfortunately players can't let go half-way over and they can't jump at it from above, but as long as the layout of the map makes sure they can't get above it and never want to let go these are only minor problems.
I also have places where you have to jump and run up a wall and then jump away from it! These work with a low-grav volume at the buttom so you can jump slightly higher, then a upwards gravits volume to pull you up and give you a little more velocity (this is so the upwards gravity volume is high enough and small enough so jumping into it from above won't throw you back up! You need the upwards velocity of your jump to make it work), and finally an upwards and backwards gravity volume that throws you away from the wall. This way you have to jump up at the wall as if you wanted to wall-run and then you have to turn around during the ascension and push forward in your new direction or else it won't throw you far enough. Apart from not having to press "jump" again when leaving the wall it feels just about right.
The little stepping-stone things that allow you to jump either very high or very far in Mirror's Edge are done with jumppads though, unfortunately. I couldn't figure out a better way for them. I tried a few different approaches with gravity volumes but I gave up because I couldn't get them to feel right. The jumppads feel pretty authentic but unfortunately players don't have to press "jump".
Last but not least, I recorded the video with "slomo 1.5", a cheat for KF, which means time (and thus the player) moves 50% faster than normal. 1 is normal, 0.125 is ZED-time, I think, 3 is Benny Hill...
1.5 felt about right.
