Fix incorrect lightmap scale multiplier

project/code/LGS/Database/Chunks/WorldRep.cs

@@ -29,6 +29,16 @@ public class WorldRep : IChunk
             DataSize = reader.ReadUInt32();
             CellCount = reader.ReadUInt32();
         }
+
+        public readonly float LightmapScaleMultiplier()
+        {
+            return Math.Sign(LightmapScale) switch
+            {
+                1 => LightmapScale,
+                -1 => 1.0f / LightmapScale,
+                _ => 1.0f,
+            };
+        }
     }
 
     public struct Cell

project/code/TMV/Mission.cs

@@ -267,7 +267,7 @@ public partial class Mission : Node3D
 
 		var renderPoly = cell.RenderPolys[polyIdx];
 		var light = cell.LightList[polyIdx];
-		var lightmapScale = worldRep.DataHeader.LightmapScale;
+		var lightmapScale = worldRep.DataHeader.LightmapScaleMultiplier();
 		var textureId = CalcBaseUV(cell, poly, renderPoly, light, textureUvs, lightmapUvs, lightmapScale, indicesOffset);
 
 		if (!surfaceDataMap.ContainsKey(textureId))