(c2e1b24e2) Fixed remote characters sliding slowly to the left in multiplayer. Happened because linear velocity was written with an accuracy of 12 bits, causing the lowest possible value to be about 1.5 cm/s. Now extremely low velocity values are rounded down to zero. The server also now quantizes the LinearVelocity/AngularVelocity values, which should make position syncing a little more reliable because the server runs the physics using the same rounded values as the clients.

Barotrauma/BarotraumaClient/Source/Characters/Animation/Ragdoll.cs

@@ -88,13 +88,13 @@ namespace Barotrauma
                     Collider.AngularVelocity = newAngularVelocity;
 
                     float distSqrd = Vector2.DistanceSquared(newPosition, Collider.SimPosition);
-                    float errorTolerance = character.AllowInput ? 0.01f : 0.1f;
+                    float errorTolerance = character.AllowInput ? 0.01f : 0.2f;
                     if (distSqrd > errorTolerance)
                     {
                         if (distSqrd > 10.0f || !character.AllowInput)
                         {
                             Collider.TargetRotation = newRotation;
-                            SetPosition(newPosition, lerp: distSqrd < 1.0f);
+                            SetPosition(newPosition, lerp: distSqrd < 5.0f);
                         }
                         else
                         {
@@ -108,8 +108,15 @@ namespace Barotrauma
                     // -> we need to correct it manually
                     if (!character.AllowInput)
                     {
-                        MainLimb.PullJointWorldAnchorB = Collider.SimPosition;
-                        MainLimb.PullJointEnabled = true;
+                        float mainLimbDistSqrd = Vector2.DistanceSquared(MainLimb.PullJointWorldAnchorA, Collider.SimPosition);
+                        float mainLimbErrorTolerance = 0.1f;
+                        //if the main limb is roughly at the correct position and the collider isn't moving (much at least),
+                        //don't attempt to correct the position.
+                        if (mainLimbDistSqrd > mainLimbErrorTolerance || Collider.LinearVelocity.LengthSquared() > 0.05f)
+                        {
+                            MainLimb.PullJointWorldAnchorB = Collider.SimPosition;
+                            MainLimb.PullJointEnabled = true;
+                        }
                     }
                 }
                 character.MemLocalState.Clear();

Barotrauma/BarotraumaClient/Source/Characters/CharacterNetworking.cs

@@ -211,6 +211,7 @@ namespace Barotrauma
                     Vector2 linearVelocity = new Vector2(
                         msg.ReadRangedSingle(-MaxVel, MaxVel, 12), 
                         msg.ReadRangedSingle(-MaxVel, MaxVel, 12));
+                    linearVelocity = NetConfig.Quantize(linearVelocity, -MaxVel, MaxVel, 12);
 
                     bool fixedRotation = msg.ReadBoolean();
                     float? rotation = null;
@@ -220,6 +221,7 @@ namespace Barotrauma
                         rotation = msg.ReadFloat();
                         float MaxAngularVel = NetConfig.MaxPhysicsBodyAngularVelocity;
                         angularVelocity = msg.ReadRangedSingle(-MaxAngularVel, MaxAngularVel, 8);
+                        angularVelocity = NetConfig.Quantize(angularVelocity.Value, -MaxAngularVel, MaxAngularVel, 8);
                     }
 
                     bool readStatus = msg.ReadBoolean();

Barotrauma/BarotraumaClient/Source/GUI/GUI.cs

@@ -656,6 +656,13 @@ namespace Barotrauma
                 msg.Timer -= deltaTime;                
                 msg.Pos += msg.Velocity * deltaTime;                
             }
+            
+            foreach (GUIMessage msg in messages)
+            {
+                if (!msg.WorldSpace) continue;
+                msg.Timer -= deltaTime;                
+                msg.Pos += msg.Velocity * deltaTime;                
+            }
         }
 
             messages.RemoveAll(m => m.Timer <= 0.0f);

Barotrauma/BarotraumaClient/Source/Physics/PhysicsBody.cs

@@ -171,9 +171,12 @@ namespace Barotrauma
                 newVelocity = new Vector2(
                     msg.ReadRangedSingle(-MaxVel, MaxVel, 12),
                     msg.ReadRangedSingle(-MaxVel, MaxVel, 12));
+                newVelocity = NetConfig.Quantize(newVelocity, -MaxVel, MaxVel, 12);
+
                 if (!fixedRotation)
                 {
                     newAngularVelocity = msg.ReadRangedSingle(-MaxAngularVel, MaxAngularVel, 8);
+                    newAngularVelocity = NetConfig.Quantize(newAngularVelocity.Value, -MaxAngularVel, MaxAngularVel, 8);
                 }
             }
             msg.ReadPadBits();