Fix (or a workaround) to characters teleporting inside/through colliders when leaving a sub (see #552). Gaps do a raycast out from the sub to see if there are obstacles outside, and if so, ragdolls place a collider at the corresponding position inside the sub. The collider is simply a straight axis-aligned line atm, so it doesn't work accurately with sloped ice/submarine walls, but does prevent the ragdoll from ending up inside the obstacles. TODO: use a few edges to approximate the shape of the obstacles more closely?

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

@@ -100,7 +100,6 @@ namespace Barotrauma
 
             foreach (Limb limb in Limbs)
             {
-
                 if (limb.pullJoint != null)
                 {
                     Vector2 pos = ConvertUnits.ToDisplayUnits(limb.pullJoint.WorldAnchorA);
@@ -137,6 +136,16 @@ namespace Barotrauma
                 }
             }
 
+            if (outsideCollisionBlocker.Enabled && currentHull.Submarine != null)
+            {
+                var edgeShape = outsideCollisionBlocker.FixtureList[0].Shape as FarseerPhysics.Collision.Shapes.EdgeShape;
+                Vector2 startPos = ConvertUnits.ToDisplayUnits(outsideCollisionBlocker.GetWorldPoint(edgeShape.Vertex1)) + currentHull.Submarine.Position;
+                Vector2 endPos = ConvertUnits.ToDisplayUnits(outsideCollisionBlocker.GetWorldPoint(edgeShape.Vertex2)) + currentHull.Submarine.Position;                
+                startPos.Y = -startPos.Y;
+                endPos.Y = -endPos.Y;
+                GUI.DrawLine(spriteBatch, startPos, endPos, Color.Gray, 0, 5);
+            }
+
             if (character.MemState.Count > 1)
             {
                 Vector2 prevPos = ConvertUnits.ToDisplayUnits(character.MemState[0].Position);

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

@@ -3,6 +3,7 @@ using FarseerPhysics;
 using FarseerPhysics.Dynamics;
 using FarseerPhysics.Dynamics.Contacts;
 using FarseerPhysics.Dynamics.Joints;
+using FarseerPhysics.Factories;
 using Microsoft.Xna.Framework;
 using System;
 using System.Collections.Generic;
@@ -96,6 +97,8 @@ namespace Barotrauma
 
         private Category prevCollisionCategory = Category.None;
 
+        private Body outsideCollisionBlocker;
+
         public PhysicsBody Collider
         {
             get
@@ -356,15 +359,23 @@ namespace Barotrauma
             if (collider[0] == null)
             {
                 DebugConsole.ThrowError("No collider configured for \"" + character.Name + "\"!");
-                collider[0] = new PhysicsBody(0.0f, 0.0f, 0.5f, 5.0f);
+                collider[0] = new PhysicsBody(0.0f, 0.0f, 0.5f, 5.0f)
-                collider[0].UserData = character;
+                {
-                collider[0].BodyType = BodyType.Dynamic;
+                    UserData = character,
-                collider[0].CollisionCategories = Physics.CollisionCharacter;
+                    BodyType = BodyType.Dynamic,
+                    CollisionCategories = Physics.CollisionCharacter
+                };
                 collider[0].FarseerBody.AngularDamping = 5.0f;
                 collider[0].FarseerBody.FixedRotation = true;
                 collider[0].FarseerBody.OnCollision += OnLimbCollision;
             }
 
+            outsideCollisionBlocker = BodyFactory.CreateEdge(GameMain.World, -Vector2.UnitX * 2.0f, Vector2.UnitX * 2.0f, "blocker");
+            outsideCollisionBlocker.BodyType = BodyType.Static;
+            outsideCollisionBlocker.CollisionCategories = Physics.CollisionWall;
+            outsideCollisionBlocker.CollidesWith = Physics.CollisionCharacter;
+            outsideCollisionBlocker.Enabled = false;
+
             UpdateCollisionCategories();
 
             foreach (var joint in LimbJoints)
@@ -492,7 +503,10 @@ namespace Barotrauma
             Structure structure = f2.Body.UserData as Structure;
 
             if (f2.Body.UserData is Submarine && character.Submarine == (Submarine)f2.Body.UserData) return false;
-            
+
+            //only collide with the ragdoll's own blocker
+            if (f2.Body.UserData as string == "blocker" && f2.Body != outsideCollisionBlocker) return false;
+
             //always collides with bodies other than structures
             if (structure == null)
             {
@@ -789,15 +803,7 @@ namespace Barotrauma
                 //in -> out
                 if (newHull == null && currentHull.Submarine != null)
                 {
-                    for (int i = -1; i < 2; i += 2)
-                    {
-                        //don't teleport outside the sub if right next to a hull
-                        if (Hull.FindHull(findPos + new Vector2(Submarine.GridSize.X * 4.0f * i, 0.0f), currentHull) != null) return;
-                        if (Hull.FindHull(findPos + new Vector2(0.0f, Submarine.GridSize.Y * 4.0f * i), currentHull) != null) return;
-                    }
-
                     if (Gap.FindAdjacent(currentHull.ConnectedGaps, findPos, 150.0f) != null) return;
-
                     Teleport(ConvertUnits.ToSimUnits(currentHull.Submarine.Position), currentHull.Submarine.Velocity);
                 }
                 //out -> in
@@ -816,6 +822,48 @@ namespace Barotrauma
             CurrentHull = newHull;
             character.Submarine = currentHull?.Submarine;
         }
+
+        private void PreventOutsideCollision()
+        {
+            if (currentHull?.Submarine == null)
+            {
+                outsideCollisionBlocker.Enabled = false;
+                return;
+            }
+
+            var connectedGaps = currentHull.ConnectedGaps.Where(g => !g.IsRoomToRoom);
+            foreach (Gap gap in connectedGaps)
+            {
+                if (gap.IsHorizontal)
+                {
+                    if (character.Position.Y > gap.Rect.Y || character.Position.Y < gap.Rect.Y - gap.Rect.Height) continue;
+                    if (Math.Sign(gap.Rect.Center.X - currentHull.Rect.Center.X) !=
+                        Math.Sign(character.Position.X - currentHull.Rect.Center.X))
+                    {
+                        continue;
+                    }
+                }
+                else
+                {
+                    if (character.Position.X < gap.Rect.X || character.Position.X > gap.Rect.Right) continue;
+                    if (Math.Sign((gap.Rect.Y - gap.Rect.Height / 2) - (currentHull.Rect.Center.X - currentHull.Rect.Height / 2)) !=
+                        Math.Sign(character.Position.X - (currentHull.Rect.Center.X - currentHull.Rect.Height / 2)))
+                    {
+                        continue;
+                    }
+                }
+
+                if (!gap.GetOutsideCollider(out Vector2? outsideColliderPos, out Vector2? outsideColliderNormal)) continue;
+
+                outsideCollisionBlocker.SetTransform(
+                    outsideColliderPos.Value - currentHull.Submarine.SimPosition, 
+                    MathUtils.VectorToAngle(outsideColliderNormal.Value) - MathHelper.PiOver2);
+                outsideCollisionBlocker.Enabled = true;
+                return;
+            }
+
+            outsideCollisionBlocker.Enabled = false;
+        }
         
         public void Teleport(Vector2 moveAmount, Vector2 velocityChange)
         {
@@ -888,6 +936,7 @@ namespace Barotrauma
             Vector2 flowForce = Vector2.Zero;
 
             FindHull();
+            PreventOutsideCollision();
 
             splashSoundTimer -= deltaTime;
 
@@ -1568,6 +1617,12 @@ namespace Barotrauma
                 b.Remove();
             }
 
+            if (outsideCollisionBlocker != null)
+            {
+                GameMain.World.RemoveBody(outsideCollisionBlocker);
+                outsideCollisionBlocker = null;
+            }
+
             if (LimbJoints != null)
             {
                 foreach (RevoluteJoint joint in LimbJoints)

Barotrauma/BarotraumaShared/Source/Map/Gap.cs

@@ -1,4 +1,5 @@
 using Barotrauma.Items.Components;
+using FarseerPhysics;
 using Microsoft.Xna.Framework;
 using System;
 using System.Collections.Generic;
@@ -13,6 +14,8 @@ namespace Barotrauma
 
         public static bool ShowGaps = true;
 
+        const float OutsideColliderRaycastInterval = 0.1f;
+
         public readonly bool IsHorizontal;
         
         //a value between 0.0f-1.0f (0.0 = closed, 1.0f = open)
@@ -26,12 +29,18 @@ namespace Barotrauma
         private float lowerSurface;
         
         private Vector2 lerpedFlowForce;
-
+        
         //if set to true, hull connections of this gap won't be updated when changes are being done to hulls
         public bool DisableHullRechecks;
         
         //can ambient light get through the gap even if it's not open
         public bool PassAmbientLight;
+        
+        //position of a collider outside the gap (for example an ice wall next to the sub)
+        //used by ragdolls to prevent them from ending up inside colliders when teleporting out of the sub
+        private Vector2? outsideColliderPos;
+        private Vector2? outsideColliderNormal;
+        private float outsideColliderRaycastTimer;
 
         public float Open
         {
@@ -191,6 +200,8 @@ namespace Barotrauma
         {
             flowForce = Vector2.Zero;
 
+            outsideColliderRaycastTimer -= deltaTime;
+
             if (open == 0.0f || linkedTo.Count == 0)
             {
                 lerpedFlowForce = Vector2.Zero;
@@ -505,7 +516,51 @@ namespace Barotrauma
                     hull1.LethalPressure += (Submarine != null && Submarine.AtDamageDepth) ? 100.0f * deltaTime : 10.0f * deltaTime;
                 }
             }
+        }
 
+        public bool GetOutsideCollider(out Vector2? simPosition, out Vector2? normal)
+        {
+            simPosition = null;
+            normal = null;
+
+            if (IsRoomToRoom || Submarine == null || open <= 0.0f) return false;
+
+            if (outsideColliderRaycastTimer <= 0.0f)
+            {
+                UpdateOutsideColliderPos((Hull)linkedTo[0]);
+                outsideColliderRaycastTimer = OutsideColliderRaycastInterval;
+            }
+
+            simPosition = outsideColliderPos;
+            normal = outsideColliderNormal;
+            return simPosition != null;
+        }
+
+        private void UpdateOutsideColliderPos(Hull hull)
+        {
+            outsideColliderNormal = null;
+            outsideColliderPos = null;
+
+            if (Submarine == null) return;
+
+            Vector2 rayDir;
+            if (IsHorizontal)
+            {
+                rayDir = new Vector2(Math.Sign(rect.Center.X - hull.Rect.Center.X), 0);
+            }
+            else
+            {
+                rayDir = new Vector2(0, Math.Sign((rect.Y - rect.Height / 2) - (hull.Rect.Y - hull.Rect.Height / 2)));
+            }
+
+            Vector2 rayStart = ConvertUnits.ToSimUnits(WorldPosition);
+            Vector2 rayEnd = rayStart + rayDir * 500.0f;
+
+            if (Submarine.CheckVisibility(rayStart, rayEnd) != null)
+            {
+                outsideColliderNormal = -rayDir;
+                outsideColliderPos = Submarine.LastPickedPosition;
+            }
         }
 
         private void UpdateOxygen()

Barotrauma/BarotraumaShared/Source/Map/Submarine.cs

@@ -75,6 +75,7 @@ namespace Barotrauma
 
         private static Vector2 lastPickedPosition;
         private static float lastPickedFraction;
+        private static Vector2 lastPickedNormal;
 
         private Md5Hash hash;
         
@@ -120,6 +121,11 @@ namespace Barotrauma
             get { return lastPickedFraction; }
         }
 
+        public static Vector2 LastPickedNormal
+        {
+            get { return lastPickedNormal; }
+        }
+
         public bool Loading
         {
             get;
@@ -593,6 +599,7 @@ namespace Barotrauma
             }
 
             float closestFraction = 1.0f;
+            Vector2 closestNormal = Vector2.Zero;
             Body closestBody = null;
             GameMain.World.RayCast((fixture, point, normal, fraction) =>
             {
@@ -616,6 +623,7 @@ namespace Barotrauma
                 if (fraction < closestFraction)
                 {
                     closestFraction = fraction;
+                    closestNormal = normal;
                     if (fixture.Body != null) closestBody = fixture.Body;
                 }
                 return fraction;
@@ -624,6 +632,7 @@ namespace Barotrauma
 
             lastPickedPosition = rayStart + (rayEnd - rayStart) * closestFraction;
             lastPickedFraction = closestFraction;
+            lastPickedNormal = closestNormal;
             
             return closestBody;
         }
@@ -636,6 +645,7 @@ namespace Barotrauma
         {
             Body closestBody = null;
             float closestFraction = 1.0f;
+            Vector2 closestNormal = Vector2.Zero;
 
             if (Vector2.Distance(rayStart, rayEnd) < 0.01f)
             {
@@ -664,6 +674,7 @@ namespace Barotrauma
                 {
                     closestBody = fixture.Body;
                     closestFraction = fraction;
+                    closestNormal = normal;
                 }
                 return closestFraction;
             }
@@ -672,6 +683,7 @@ namespace Barotrauma
 
             lastPickedPosition = rayStart + (rayEnd - rayStart) * closestFraction;
             lastPickedFraction = closestFraction;
+            lastPickedNormal = closestNormal;
             return closestBody;
         }