[BUG] Quantum Physics Collisions

This is another bug related to Physics Constraints.

As you can see here the collision I can trace with complex trace is at 2 locations at once:

You can see the actor I trace in the upper left, the collisions are made visible with Show Collisions.

Location 1: The location where I detached my actor from the component that is physics constrained

Location 2. I attached the actor to a dummy actor then changed the location of that dummy actor (Changing the location without a dummy actor is also a bug)

Note: I don’t know quantum physics but since it is at multiple locations at once I thought there might be something related. :slight_smile: It also appears that every time I do this again it creates another ghost collision that I can trace.

My other physics constraints bugs are here: [BUG] Detach breaks collision - World Creation - Unreal Engine Forums

Hi Davision,

It looks like your issue requires several features to be implemented in order to properly test it. Could you provide your project or a test project that showcases the issue? Make sure to provide as detailed as possible reproduction steps with the project.

Also, was the object manipulation created in code or blueprint?

If the project is to large or you aren’t comfortable uploading it here, please feel free to send me a link to download it by private message over the Forums.

It is all blueprint.

I started a new project for it but I can’t get the collision of the actor I attach to be considered for the physics simulation with the physics constraint anymore. It is like it only attaches the visuals now but not the collision. The only way I can get a collision working with it now is by only using a spawned component instead and instead of attaching anything just making that spawned component a physics constrained object. But that is not what I need.

My guess is that it was never meant to be possible that you can attach a collision/object to the physics simulation of a physics constraint? Like It can only be a component without anything attached that can be used with a physics constraint. Please correct me if I’m wrong.
Then I somehow bypassed that limitation in my other project and that resulted in all these bugs and crashes. The collision of the attached actor there in the gif is working with the physics constraint physics but I can’t figure out how I made it work.

I can still give you the project I started for it though, if you like to test more with that.

Yeah, feel free to send me a link to download the project. I’m sorry if I’m misunderstanding you but I’m still not 100% clear on what you are describing, so just make sure to include throughout repro steps with the project so I can see exactly what you mean.

I made it now mostly work what I wanted to get working but with some big workarounds. I basically use a extra spawned component now of which the collision works, when placed I get rid of that and place the actual actor there.
but I still encountered bugs:
I was not able to reset the location of the component. Either the location was off or the physics simulation was not working anymore. I tried lots of combinations with break constraint, no break, attach again, etc.
So everytime I need to reset the location I now destroy the component and create an new one, which works fine but is a bit silly.
I also found out that there needs to be a delay after changing the location, so before making the set constraint objects and set simulate physics.
I also had it crashing again but not sure why.

The whole thing is basically a drag and drop feature with actors. Where the dragging is with a physic constraint and the dragged object collides physic simulated. Sound simply but as I had to experience it myself it is not all.