From b47a7536c48887922c93ce87feb986e616a4d342 Mon Sep 17 00:00:00 2001
From: Jarrod Doyle <thejarroddoyle@gmail.com>
Date: Mon, 4 Nov 2024 18:08:54 +0000
Subject: [PATCH] Ray traces now continue through any water they hit (unless
 the water surface is the target)

---
 KeepersCompound.Lightmapper/LightMapper.cs | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/KeepersCompound.Lightmapper/LightMapper.cs b/KeepersCompound.Lightmapper/LightMapper.cs
index 4c81ff1..94c6adf 100644
--- a/KeepersCompound.Lightmapper/LightMapper.cs
+++ b/KeepersCompound.Lightmapper/LightMapper.cs
@@ -612,13 +612,23 @@ public class LightMapper
     
     private bool TraceRay(Vector3 origin, Vector3 target)
     {
-        var direction = target - origin;
-        var hitResult = _scene.Trace(new Ray
+        var hitDistanceFromTarget = float.MinValue;
+        var hitSurfaceType = SurfaceType.Water;
+        while (hitDistanceFromTarget < -MathUtils.Epsilon && hitSurfaceType == SurfaceType.Water)
         {
-            Origin = origin,
-            Direction = Vector3.Normalize(direction),
-        });
-        return hitResult && Math.Abs(hitResult.Distance - direction.Length()) < MathUtils.Epsilon;
+            var direction = target - origin;
+            var hitResult = _scene.Trace(new Ray
+            {
+                Origin = origin,
+                Direction = Vector3.Normalize(direction),
+            });
+
+            hitDistanceFromTarget = hitResult.Distance - direction.Length();
+            hitSurfaceType = _triangleTypeMap[(int)hitResult.PrimId];
+            origin = hitResult.Position += direction * MathUtils.Epsilon;
+        }
+
+        return Math.Abs(hitDistanceFromTarget) < MathUtils.Epsilon;
     }
 
     private void SetAnimLightCellMaps()