I have a project based off the VR template. I made the template multiplayer. I have physics actors you can throw. I can pick them up and throw them.
Issue 1:
When I throw the actor into the air and catch it sometimes on the client (host/server works fine) the object will not be in the players hand and will be invisible. When I release the actor (onDrop of the grab component) it will reappear where it is on the server. I tried making an update event when you grab the actor it updates the location of the actor but I still have the issue sometimes.
Issue 2
Sometimes the client can’t throw the actor. If the actor is thrown and comes to a complete stop you can pick it up and throw it every time. If the actor is still moving and I pick it up sometimes it will not throw and does the thing where the actor just falls from it’s current location (no added velocity). If I pick up the actor when it won’t apply velocity (where it falls to the ground when released) I can use my other hand to switch the object to my other hand and then I can throw the actor every time.
My physics actor is a little complex. When you throw/drop the actor it gets the velocity of the static mesh and sends that info to the vrpawn and spawns an actor at the same location then applies velocity and destroys the original actor. It seems to work well but these issues need to be fixed.
Video shows both issues. First the issue where you catch it while it’s moving and can’t throw again and then the issue where you catch it and it disappears.
Any ideas would be helpful. Thank you.
Pic of the grab event in my vrpawn where it might be happening. Obviously it could be an issue inside the blueprint for the actor also.
Networking problems like these could be pretty challenging to debug.
I can try to suggest a few things that may provide a direction for debugging.
First question: Is your project server authoritative? I am going to assume this is a yes for my next suggestions.
Physics objects in general are very complicated to replicate over the network. I am unsure if newer Unreal’s have made them significantly better, but I personally found them to be pretty unstable.
The simplest way to approach your problem is to make your architecture in a way where only the server is making the decisions.
The only thing the client is seeing is replicated Transforms. Let the client send calls to the server about its inputs, and run all of the grab/pick etc… code directly on the server. It’s not possible for me to tell if that is what you are doing in your code.
The second issue you have is the way your spawn behaviour is setup. Since you are adding/destroying very fast moving/responsive physics objects you aren’t going to get very reliable results. (GENERALLY SPEAKING)
You could either try to collapse all the behaviour you need into the same object, or try to spawn multiple objects from the start, so there is less friction of having network ready objects in span of a frame.
Finally, if possible, setup your project with third person character so you can test these concepts very quickly on the same monitor. I’ve found it difficult to debug these types of problems directly in the headsets.
