Righty - it was about time I did another one of these, so this time, let's make ourselves a 4-Way Gothic Fan Vault in just 30-odd easy steps !
Of all the various vault types this is perhaps the most challenging to model so hopefully I can help to show how best to get started with your under-structures...
You can use these techniques as the basis for this sort of thing...
This is all-quads but no SDS, and medium poly density so stands up to some fairly close camera-work and with a few small modifications is suitable for turning into a MoGraph maze of them if needed... anyway - enjoy.
Ref Image Here.
If you'd like Part 2 where, where we could make some fan struts, and a plinth centrepiece and sort out the UVs, let me know below !
CBR