Location Fighting

[Bobert13]

The game engine often gets confused, about a player's true whereabouts, when the player is near the meeting point of a horizontal collision plane and a vertical one. This has few symptoms when actually playing, but is quite easy to see when you've died and are spectating a team mate. You can literally see their character jitter back and forth between being on top of the structure and alongside the structure. I believe this location fighting is a factor in many of the game's bugs (unable to move and/or attack, stuck in a blocking animation, other players can't see your animations, etc.). Falling while doing a jump attack when your character is in a "location fighting" state or being struck by an opponent while in a "location fighting" state are both reproducible triggers for the aforementioned glitches.

Without any real experience working with the Unreal Engine, I do have a couple of ideas on how to eliminate or at least reduce location fighting. The first idea would be to make the outward edge, where the two collision planes meet, less than a 90 degree angle. Essentially, you'd inset the bottom of the collision plane, slightly, so that the vertical plane isn't quite vertical. The second, would be to try the opposite. Instead of insetting the bottom of the plane, possibly out-setting it would resolve the issue. The third Idea would be to smooth the corner where the two planes meet with a very small plane that's at a 45 degree angle. The support team behind Unreal may have a true solution to this issue, or at least better suggestions. It may be that the collision planes for the maps are fine, but the collision points of the character models need to be tinkered with. Perhaps adding a shallow pyramid shape to the bottom of their collision boxes (assuming they're rectangular) will have a beneficial effect.

As a player, this issue is probably the second-most game-breaking thing to me, right now. Right behind infinite combos and exploitable semi-infinites (double JL, Danmei spam, etc.). Hopefully, this report is helpful to you guys over at CodeBrush, and you can get this stuff resolved.

[$cno0B!]

As a rule of thumb. Dont fight on stairs :D

[Sunchips]

This issue is definitely reproducable with the information you gave, although I would advise against tinkering with collision in that manner, since other games have had success without collision problems using UE. Also, there is no guarantee that changing the "shape" of the collision will alleviate the issue, since collision doesn't necessarily need to be done using "shapes", it can also be done in certain circumstances using prediction math, which would make more sense within the context of a state-based syncrhonous engine.