Normal•2y ago

Moving a kinematic body with .MovePosition() sometimes doesn't update the position for all players

I've been experiencing strange results with moving rigidbodies with my own velocity calculation using MovePosition. For the owner of the object everything works fine but sometimes other players can't see the object moving.

kapa.ai•6/3/24, 7:37 PM

Hi @gubebra. I'm kapa.ai, your friendly support bot. I will try to answer your question by searching through the knowledge base.

kapa.ai•6/3/24, 7:37 PM

----------------------
This issue might be related to the ownership of the component in NormalVR. In a multiplayer environment, a game object and its transform can exist on multiple clients. This means that there are multiple copies that all claim to know the position of this object, but only one of them can be considered the source of truth. This is where ownership comes in.

treats the client that owns the object as the source of truth. All other clients follow along with the owner's copy of the transform or rigidbody. This means that in order to move an object with a component on it, you must be the owner of the component.

You can request ownership of a component by calling or by using the Request Ownership button in the editor inspector. A is available for immediate use after is called. Normcore will assume the call is going to succeed, and will roll back any state changes automatically if the call is rejected by the server (source (https://normcore.io/documentation/realtime/realtimetransform#how-it-works)).

If you're trying to directly move an object, make sure to mark it kinematic. Doing so lets PhysX know that you're controlling its position and it should not simulate the object directly. It also tells that it should not clear ownership when the object goes to sleep (source (https://normcore.io/documentation/realtime/networked-physics#realtimetransform--physics)).

kapa.ai•6/3/24, 7:37 PM

Also, if you've added a component to your game object and it keeps getting reset back to where it started, this is why. You're not the owner, and therefore the datastore values are treated as the source of truth (source (https://normcore.io/documentation/realtime/networked-physics#ownership--physics)).

Lastly, if the object has a Rigidbody on it, make sure to use the and methods in (source (https://normcore.io/documentation/realtime/realtimetransform#dont-reparent-game-objects-with-realtimetransform-on-them)).
----------------------
Note: you can ask me a follow up question by @ mentioning me again

----------------------

kapa.ai•6/3/24, 7:37 PM

@599054560270483456 kapa.ai is still learning and improving, please let us know how it did by reacting below

maxweisel•6/3/24, 7:38 PM

You’re moving it once right? not over multiple frames?

gubebraOP•6/3/24, 7:38 PM

Hi Max, I'm moving it for multiple frames

gubebraOP•6/3/24, 7:39 PM

The player is holding the object and moving around

maxweisel•6/3/24, 7:39 PM

@NormalMark this is a bug I’d love to include in the bug bash. It goes out in a single unreliable packet and gets dropped. Chris wrote some tools to make it so we can make an “unreliable reliable” property that sends a final reliable packet after the property hasn’t changed for a network frame.

Ggubebra The player is holding the object and moving around

maxweisel•6/3/24, 7:39 PM

oh interesting. and none of the frames update or you see a dropped frame occasionally?

gubebraOP•6/3/24, 7:41 PM

No, the object doesn't move for some players even when the owner is holding it. Everything seems to be right, the owner, the movement and of course the owner sees the object moving in his hand

maxweisel•6/3/24, 7:42 PM

do any other remote players not see the movement? this sounds like potentially an ownership issue

gubebraOP•6/3/24, 7:43 PM

I do disable/enable the gameObject sometimes to save some processing. But I made sure to do it some frames before and all players have the object active before anyone has the chance to grab it

Mmaxweisel do any other remote players not see the movement? this sounds like potentially a...

gubebraOP•6/3/24, 7:44 PM

And it seems to be only happening sometimes

maxweisel•6/3/24, 7:45 PM

if the data is making it to the server and out to other clients, it’s hard for me to imagine how some clients aren’t processing it. that said enabling / disabling the game object could definitely mess that up. RealtimeComponents don’t support that very well. Instead we recommend turning off other components / renderers or making a child game object that you enable/disable and put everything else on that

gubebraOP•6/3/24, 7:46 PM

Oh so you're saying instead of disabling the realtimeComponent add a child to that object (the meshRenderer) and only disable that?

maxweisel•6/3/24, 7:46 PM

yeah

gubebraOP•6/3/24, 7:48 PM

Alright makes sense, I'm going to try doing this then, thanks fo the help Max

maxweisel•6/3/24, 7:51 PM

sure thing!