Multiple particle emitters can be be attached to a background sprite, hydrothermal vents push characters and subs upwards, tweaked hydrothermal smoke particles & trigger positioning

Barotrauma/BarotraumaClient/Source/Map/Levels/BackgroundSprite/BackgroundSpritePrefab.cs

@@ -1,12 +1,14 @@
-using Microsoft.Xna.Framework;
+using Barotrauma.Particles;
+using Microsoft.Xna.Framework;
+using System.Collections.Generic;
 using System.Xml.Linq;
 
 namespace Barotrauma
 {
     partial class BackgroundSpritePrefab
     {        
-        public readonly Particles.ParticleEmitterPrefab ParticleEmitterPrefab;
-        public readonly Vector2 EmitterPosition;
+        public readonly List<ParticleEmitterPrefab> ParticleEmitterPrefabs;
+        public readonly List<Vector2> EmitterPositions;
 
         public readonly XElement SoundElement;
         public readonly Vector2 SoundPosition;