Collision boxes for stairways

I play Blacklight: Retribution a lot which was built in Unreal 3 I believe.
Zombie Studios.
I see characters die on stairs and then their bodies just float horizontally above the angle of the stairs or steps.
It looks like the collisions set for the stairs or over simplified and I just wonder why that is.
If you make collision boxes very tight around individual steps of the staircase will that improve the way
characters interact with it / fall on top of it?
In other words their bodies should “fold” inward and “curve” around individual steps rather than just float
above it in the air.
Just wondering if there is a good reason why this happens.
Is it just “lazy” programming? Or might it slow down the game play a lot if the collisions are too detailed?
In other words is there a “resolution” issue with collision boxes?
Like too many poly’s would slow down the game … kinda.

Thank you.


I have moved this to content creation as its not feedback for epic and it fits better here.

to your question, it might have been done that way for better performance as lots of collisions can have a fairly large cost, it might also have been done that way because when walking up stairs you don’t always need accurate collision on each step(like in an FPS you probably wouldn’t notice whether or not the players feet are accurately colliding with each step) and quite a few games just have simple slopes instead, it could have also been done like that for both those reasons, oh and its quicker to make meshes with simple collision so that could be a factor as well. if the player is just floating horizontally above the steps it might be caused by the physics asset/ragdoll.

hope that helps:)

Great thank you.

I suspect it may have more to do with how it looks from the player’s perspective when you climb the stairs in terms of preserving some smooth camera motion. Also less likely to get hung up on things if the collision isn’t a lot of 90 degree angles. You’ll see this being done with stuff that juts out from walls to sometimes for similar reasons I think.

A lot of times hard collisions like stairs will cause the players interaction to be very jarring, stairs tend to be the worse as they they have a total vertical attached to a complete horizontal which will cause the collision engine to stop your character completely push it straight up in the air and free it to move forward again. Ramps are just a much smoother way of transitioning the character with less jarring effects. There is a compromise between the two, where you put detents where the stair edges are, and make ramps between them, the detents should be angled and never straight up and down.

O.k. Visnarel thank you great info.
If it was me I would just build a single collision ramp further “into” the mesh of the stairs and
rather have the feet go into the steps than float above it … but on 2nd thought that might look terrible too :slight_smile: