Fix laser collision logic wrt transparent entities (#1018)

Content.Server/GameObjects/Components/Weapon/Ranged/Hitscan/HitscanWeaponComponent.cs

@@ -93,10 +93,11 @@ namespace Content.Server.GameObjects.Components.Weapon.Ranged.Hitscan
             var userPosition = user.Transform.WorldPosition; //Remember world positions are ephemeral and can only be used instantaneously
             var angle = new Angle(clickLocation.Position - userPosition);
 
-            var ray = new CollisionRay(userPosition, angle.ToVec(), (int)(CollisionGroup.Impassable | CollisionGroup.MobImpassable));
-            var rayCastResults = IoCManager.Resolve<IPhysicsManager>().IntersectRay(user.Transform.MapID, ray, MaxLength, user).ToList();
+            var ray = new CollisionRay(userPosition, angle.ToVec(), (int)(CollisionGroup.Opaque));
+            var rayCastResults = IoCManager.Resolve<IPhysicsManager>().IntersectRay(user.Transform.MapID, ray, MaxLength, user, returnOnFirstHit: false).ToList();
 
-            if (rayCastResults.Count == 1)
+            //The first result is guaranteed to be the closest one
+            if (rayCastResults.Count >= 1)
             {
                 Hit(rayCastResults[0], energyModifier, user);
                 AfterEffects(user, rayCastResults[0], angle, energyModifier);

Resources/Prototypes/Entities/Mobs/human.yml

@@ -109,6 +109,7 @@
       - VaultImpassable
       - SmallImpassable
       layer:
+      - Opaque
       - MobImpassable
   - type: Input
     context: "human"