KeepersCompound.Lightmapper/LightMapper.cs

@@ -699,11 +699,20 @@ public class LightMapper
                             
                             var light = _lights[lightIdx - 1];
 
-                            // If the light is behind the plane we'll never be directly lit by this light.
-                            // Additionally, if the distance from the plane is more than the light's radius
-                            // we know no points on the plane will be lit.
-                            var planeDist = MathUtils.DistanceFromPlane(plane, light.Position);
-                            if (planeDist <= MathUtils.Epsilon || planeDist > light.Radius)
+                            // Check if plane normal is facing towards the light
+                            // If it's not then we're never going to be (directly) lit by this
+                            // light.
+                            var centerDirection = renderPoly.Center - light.Position;
+                            if (Vector3.Dot(plane.Normal, centerDirection) >= 0)
+                            {
+                                continue;
+                            }
+
+                            // If there aren't *any* points on the plane that are in range of the light
+                            // then none of the lightmap points will be so we can discard.
+                            // The more compact a map is the less effective this is
+                            var planeDist = Math.Abs(MathUtils.DistanceFromPlane(plane, light.Position));
+                            if (planeDist > light.Radius)
                             {
                                 continue;
                             }
@@ -730,7 +739,7 @@ public class LightMapper
                                     continue;
                                 }
                                 
-                                if (!TraceOcclusion(light.Position, point))
+                                if (TraceRay(light.Position, point))
                                 {
                                     strength += targetWeights[idx] * light.StrengthAtPoint(point, plane, settings.AnimLightCutoff);
                                 }
@@ -817,58 +826,81 @@ public class LightMapper
         {
             var offset = offsets[i];
             var pos = basePosition + offset;
-
+            
+            // Embree has robustness issues when hitting poly edges which
+            // results in false misses. To alleviate this we pre-push everything
+            // slightly towards the center of the poly.
+            var centerOffset = polyCenter - pos;
+            if (centerOffset.LengthSquared() > MathUtils.Epsilon)
+            {
+                pos += Vector3.Normalize(centerOffset) * MathUtils.Epsilon;
+            }
+            
             // If we can't see our target point from the center of the poly
-            // then we need to clip the point to slightly inside the poly
-            // and retrace to avoid two problems:
+            // then it's outside the world. We need to clip the point to slightly
+            // inside the poly and retrace to avoid three problems:
             // 1. Darkened spots from lightmap pixels whose center is outside
             //    the polygon but is partially contained in the polygon
             // 2. Darkened spots from linear filtering of points outside the
             //    polygon which have missed
-            var occluded = TraceOcclusion(polyCenter + planeMapper.Normal * 0.25f, pos);
-            if (occluded)
+            // 3. Darkened spots where centers are on the exact edge of a poly
+            //    which can sometimes cause Embree to miss casts
+            var inPoly = TraceRay(polyCenter + planeMapper.Normal * 0.25f, pos);
+            if (!inPoly)
             {
                 var p2d = planeMapper.MapTo2d(pos);
                 p2d = MathUtils.ClipPointToPoly2d(p2d, v2ds);
                 pos = planeMapper.MapTo3d(p2d);
             }
-            
+
             tracePoints[i] = pos;
         }
         
         return tracePoints;
     }
     
-    private bool TraceOcclusion(Vector3 origin, Vector3 target)
+    private bool TraceRay(Vector3 origin, Vector3 target)
     {
-        var direction = target - origin;
-        var ray = new Ray
+        var hitDistanceFromTarget = float.MinValue;
+        var hitSurfaceType = SurfaceType.Water;
+        while (hitDistanceFromTarget < -MathUtils.Epsilon && hitSurfaceType == SurfaceType.Water)
         {
-            Origin = origin,
-            Direction = Vector3.Normalize(direction),
-        };
-        
-        // Epsilon is used here to avoid occlusion when origin lies exactly on a poly
-        return _scene.IsOccluded(new ShadowRay(ray, 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;
+        }
+
+        // A large epsilon is used here to fix shadow acne on sloped surfaces :)
+        return Math.Abs(hitDistanceFromTarget) < 10 * MathUtils.Epsilon;
     }
 
-    // TODO: direction should already be normalised here
+    // TODO: Can this be merged with the above?
     private bool TraceSunRay(Vector3 origin, Vector3 direction)
     {
         // Avoid self intersection
         origin += direction * MathUtils.Epsilon;
         
-        var hitResult = _scene.Trace(new Ray
+        var hitSurfaceType = SurfaceType.Water;
+        while (hitSurfaceType == SurfaceType.Water)
         {
-            Origin = origin,
-            Direction = Vector3.Normalize(direction),
-        });
-
-        if (hitResult)
-        {
-            return _triangleTypeMap[(int)hitResult.PrimId] == SurfaceType.Sky;
+            var hitResult = _scene.Trace(new Ray
+            {
+                Origin = origin,
+                Direction = Vector3.Normalize(direction),
+            });
+            
+            hitSurfaceType = _triangleTypeMap[(int)hitResult.PrimId];
+            origin = hitResult.Position += direction * MathUtils.Epsilon;
         }
-        return false;
+        
+        return hitSurfaceType == SurfaceType.Sky;
     }
 
     private void SetAnimLightCellMaps()

KeepersCompound.Lightmapper/MeshBuilder.cs

@@ -43,8 +43,9 @@ public class MeshBuilder
             var cellIdxOffset = 0;
             for (var polyIdx = 0; polyIdx < numPolys; polyIdx++)
             {
-                // There's 2 types of poly that we need to include in the mesh:
+                // There's 3 types of poly that we need to include in the mesh:
                 // - Terrain
+                // - Water surfaces
                 // - Door vision blockers
                 //
                 // Door vision blockers are the interesting one. They're not RenderPolys at all, just flagged Polys.
@@ -55,8 +56,7 @@ public class MeshBuilder
                 }
                 else if (polyIdx < numRenderPolys)
                 {
-                    // we no longer want water polys :)
-                    continue;
+                    primType = SurfaceType.Water;
                 }
                 else if ((cell.Flags & 8) != 0)
                 {
@@ -118,7 +118,7 @@ public class MeshBuilder
             var modelPath = campaignResources.GetResourcePath(ResourceType.Object, modelName);
             if (modelPath == null)
             {
-                Log.Warning("Failed to find model file: {Name}", modelName);
+                Log.Warning("Failed to find model file: {Path}", modelPath);
                 continue;
             }