Well, as per the question. Hit seems to work by enabling CCD, but Overlap, which should be easier to detect, seems impossible.
Physical simulation is effective, and the diameter is about 1cm and the speed is about 1000m/s. Overlap is handled by capsule collision. Apparently someone has managed to get overlap to work six times faster than this, but I have no idea what the settings are. Can someone please give me some advice?
Hello,
CCD should do the trick here. I would double check if your overlap events are enabled and triggering at lower speeds, then enable CCD.
The reason why it doesn’t trigger without it is because the object can be moving so fast, in one frame it goes from being say in front of a collision to being behind the object and its collision.
CCD works on hits but not on overlaps.
You need to sweep collision on fast moving actors.
I’ve tried researching sweep collision but haven’t found any clear results. Does it mean covering projectiles with larger collisions?
I have set spherical collision on the root, set Sweep in Projectile Movement, and enabled CCD, but it doesn’t work. Overlap speeds above 300 m/s rapidly become unreliable.
At speeds above 1000 m/s, more than half of a thin object (less than 0.5 m thick) will pass through, and objects with no thickness, such as landscapes, will not be detected at all.
It’s strange that overlap doesn’t work as well as Hit does.
I tested it yesterday after work and I was able to get overlap events on 1 unreal unit thick collider when moving at 100,000 velocity. I think that translates to 1000m/s and that was without CCD.
So it’s a bit confusing why it doesn’t work for you. I would venture a guess that it has something to do with collision settings both on projectile and object you want to overlap.
What collision settings do Hit work for but Overlap doesn’t? Does such a thing exist?
The object I’m using for collision is a skeletal mesh physics asset. There maybe a problem with this, but I don’t know what that problem is. Or maybe something broke in the new 5.7…
Sweeping means to sphere trace the last location to new at intervals. Preferably sub-stepped.
You can do it on tick.
PMC does this by default if physics is disabled.
So does that mean it won’t work if physics is enabled? This may not be a technique that works in my use case.
If you enable physics sim PMC handles initial velocity, then physics takes over.
Hover the component. It’ll tell you this in the description.
Without physics you get sub-stepped interpolated movement with collision sweeps. This is default settings. CCD isn’t required.
I’ve fully tested it with a 0.1 cm radius sphere collision hitting sheet planes at 600,000 cm/s velocity.
I have a vid covering this. I’ll see if I can dig it up.
Thank you for your kindness. It seems that disabling physics makes overlap much easier. However, I really want to use physics, so this approach is not an option. It will be completely incompatible with my previous work.
So I’ll try to find another way.