10/03/2013 10:02 PMMy WD will be waving it's arms as though he's casting, but the fiery swirl is not visible and no damage is dealt. It *seems* to continue to drain mana and the only way to recover is to release the spell and re-cast again.
Posted by Puny
I don't think it drains mana, but the mana doesn't regenerate.
Known situations are more obvious when using PTV. The most likely reason is we have sufficient mana to perform the initial cast, but insufficient mana to produce the first tick of CoB.
Without PTV, initial cast = 221 mana, each tick uses 33 mana. When we have 240 mana remaining and begin CoB, we see all the animation but no actual bat or damage.
According to research by GunnersDream, we consume 221 mana upon casting and initiate the first tick consuming 33 mana after 2 frames (1/30th of a second). http://us.battle.net/d3/en/forum/topic/9572528254?page=1
To replay this problem, your mana must be between 222 and 254. Using PTV will have a 30% wider mana range to recreate the problem, which makes the situation happen more often.
IMO, Blizzard programmers should have made the initial consumption 155 mana, then when we consume 2 ticks ( = 1 channel), we use up exactly 221 mana. If they coded it this way, it will be exactly as their tooltip describes.
However, even if they coded it this way, the "bug" is still existent, they are only shifting the "bug" mana bracket lower. To solve it, they must not allow any CoB casting below 254 mana, before factoring in mana discount skills and items. Depending on the mana discount skills or items, the minimum permissible mana to cast CoB will be lower.