Intersect ray hit RID is different each time?

[gitcatrat]

Godot version:
3.2.stable.mono

OS/device including version:
macOS Catalina 10.15.3/MacBook Pro

Issue description:
DirectSpaceState.IntersectRay hit object RID is different each time, even if same hit body.

I didn't even notice this before because I used nodes and collider (and its Name) to identify the hit target but now that I've moved some of my stuff to use Servers API directly, I have no way to identify the hit target if RID is constantly changing.

Maybe it's supposed to change? I have no idea, couldn't find any information about it. I was going to use RID as a dictionary key to get my data instance but this condition fails:

public static Dictionary<RID, Enemy> enemyRids;
// ...
if (enemyRids.ContainsKey(hitRID)) { /* ... */ }

Steps to reproduce:
Sorry for C#, I've used GDScript only few times.

public override void _PhysicsProcess(float delta) {
  if (doRayCast) {
    var spaceState = GetWorld().DirectSpaceState;
    var hit = spaceState.IntersectRay(from, to);
    Debug.Log(hit["rid"]); // different each time, even if same hit body
    doRayCast = false;
  }
}

Reproduction project:
issue.zip

Screenshot of RIDs (Newtonsoft JSON serializer) when ray-casting same body:

[KoBeWi]

I tried with GDScript and the RID is constant.

Any reproduction project for this?

[gitcatrat]

Was about to make one but then I stumbled on this #35897..

[gitcatrat]

@KoBeWi Managed to solve previously mentioned issue by running NuGet restore.

Project: issue.zip
Blue (left) cube is node-based, red (right) cube is added with Servers. Both have the issue.

[KoBeWi]

Sooo, when you change the debug line to
Debug.Log((hit["rid"] as RID).GetId());
you get consistent IDs. So the RID is indeed not changing, but when you print it directly it might be printing some instance data (each RID might be unique object even if they have the same ID).

No idea what is the "NativeInstance" stuff, but otherwise seems like it's working correctly.

[gitcatrat]

Okay, so the bottom line is that RID comparison is not reliable and it can't be used as a key (in dictionary for example). But at least there's a way to get the ID that can be used in these situations.

Thanks, I'll make a quick test in my project to see if it solves my issue.

[KoBeWi]

Okay, so the bottom line is that RID comparison is not reliable and it can't be used as a key (in dictionary for example).

This is weird actually, because RID is a built-in type, so they should compare properly. It is possible that it's only C# issue, this probably requires some more testing.

[gitcatrat]

@KoBeWi Fixed in Godot 4.0 beta 17, I have no idea which version fixed it.
I'm not going to close this myself in case you have some other plans.

[akien-mga]

Fixed in 4.0.