diff --git a/SabreTools.Models/BSP/BspModel.cs b/SabreTools.Models/BSP/BspModel.cs
index af9b0b9..87254f6 100644
--- a/SabreTools.Models/BSP/BspModel.cs
+++ b/SabreTools.Models/BSP/BspModel.cs
@@ -27,17 +27,17 @@ namespace SabreTools.Models.BSP
         /// <summary>
         /// Defines bounding box
         /// </summary>
-        public Vector3D Mins;
+        public Vector3D? Mins;
 
         /// <summary>
         /// Defines bounding box
         /// </summary>
-        public Vector3D Maxs;
+        public Vector3D? Maxs;
 
         /// <summary>
         /// Coordinates to move the coordinate system
         /// </summary>
-        public Vector3D OriginVector;
+        public Vector3D? OriginVector;
 
         /// <summary>
         /// Index into nodes array
diff --git a/SabreTools.Models/BSP/BspTexinfo.cs b/SabreTools.Models/BSP/BspTexinfo.cs
index c739cc3..b36788d 100644
--- a/SabreTools.Models/BSP/BspTexinfo.cs
+++ b/SabreTools.Models/BSP/BspTexinfo.cs
@@ -22,7 +22,7 @@ namespace SabreTools.Models.BSP
         /// <summary>
         /// S-vector
         /// </summary>
-        public Vector3D SVector;
+        public Vector3D? SVector;
 
         /// <summary>
         /// Texture shift in the S direction
@@ -32,7 +32,7 @@ namespace SabreTools.Models.BSP
         /// <summary>
         /// T-vector
         /// </summary>
-        public Vector3D TVector;
+        public Vector3D? TVector;
 
         /// <summary>
         /// Texture shift in the T direction
diff --git a/SabreTools.Models/BSP/DispInfo.cs b/SabreTools.Models/BSP/DispInfo.cs
index 182bce8..96b5de5 100644
--- a/SabreTools.Models/BSP/DispInfo.cs
+++ b/SabreTools.Models/BSP/DispInfo.cs
@@ -25,7 +25,7 @@ namespace SabreTools.Models.BSP
         /// <summary>
         /// Start position used for orientation
         /// </summary>
-        public Vector3D StartPosition;
+        public Vector3D? StartPosition;
 
         /// <summary>
         /// Index into LUMP_DISP_VERTS.
diff --git a/SabreTools.Models/BSP/DispVert.cs b/SabreTools.Models/BSP/DispVert.cs
index c30fbc9..b141b65 100644
--- a/SabreTools.Models/BSP/DispVert.cs
+++ b/SabreTools.Models/BSP/DispVert.cs
@@ -18,7 +18,7 @@ namespace SabreTools.Models.BSP
         /// <summary>
         /// Vector field defining displacement volume.
         /// </summary>
-        public Vector3D Vec;
+        public Vector3D? Vec;
 
         /// <summary>
         /// Displacement distances.
diff --git a/SabreTools.Models/BSP/LeafAmbientLighting.cs b/SabreTools.Models/BSP/LeafAmbientLighting.cs
index 646a512..3c7073e 100644
--- a/SabreTools.Models/BSP/LeafAmbientLighting.cs
+++ b/SabreTools.Models/BSP/LeafAmbientLighting.cs
@@ -16,7 +16,7 @@ namespace SabreTools.Models.BSP
     [StructLayout(LayoutKind.Sequential)]
     public sealed class LeafAmbientLighting
     {
-        public CompressedLightCube Cube;
+        public CompressedLightCube? Cube;
 
         /// <summary>
         /// Fixed point fraction of leaf bounds
diff --git a/SabreTools.Models/BSP/OccluderData.cs b/SabreTools.Models/BSP/OccluderData.cs
index dad2784..af21ca6 100644
--- a/SabreTools.Models/BSP/OccluderData.cs
+++ b/SabreTools.Models/BSP/OccluderData.cs
@@ -27,12 +27,12 @@ namespace SabreTools.Models.BSP
         /// <summary>
         /// Minima of all vertices
         /// </summary>
-        public Vector3D Mins;
+        public Vector3D? Mins;
 
         /// <summary>
         /// Maxima of all vertices
         /// </summary>
-        public Vector3D Maxs;
+        public Vector3D? Maxs;
 
         /// <remarks>Since v1</remarks>
         public int Area;
diff --git a/SabreTools.Models/BSP/Overlay.cs b/SabreTools.Models/BSP/Overlay.cs
index da46db7..4d4c6e9 100644
--- a/SabreTools.Models/BSP/Overlay.cs
+++ b/SabreTools.Models/BSP/Overlay.cs
@@ -41,8 +41,8 @@ namespace SabreTools.Models.BSP
         [MarshalAs(UnmanagedType.ByValArray, SizeConst = 4)]
         public Vector3D[]? UVPoints = new Vector3D[4];
 
-        public Vector3D Origin;
+        public Vector3D? Origin;
 
-        public Vector3D BasisNormal;
+        public Vector3D? BasisNormal;
     }
 }
\ No newline at end of file
diff --git a/SabreTools.Models/BSP/Plane.cs b/SabreTools.Models/BSP/Plane.cs
index ad81add..422ad04 100644
--- a/SabreTools.Models/BSP/Plane.cs
+++ b/SabreTools.Models/BSP/Plane.cs
@@ -25,7 +25,7 @@ namespace SabreTools.Models.BSP
         /// <summary>
         /// The planes normal vector
         /// </summary>
-        public Vector3D NormalVector;
+        public Vector3D? NormalVector;
 
         /// <summary>
         /// Plane equation is: vNormal * X = fDist
diff --git a/SabreTools.Models/BSP/StaticPropLump.cs b/SabreTools.Models/BSP/StaticPropLump.cs
index deb90cf..7a56704 100644
--- a/SabreTools.Models/BSP/StaticPropLump.cs
+++ b/SabreTools.Models/BSP/StaticPropLump.cs
@@ -39,12 +39,12 @@ namespace SabreTools.Models.BSP
         /// <summary>
         /// Origin
         /// </summary>
-        public Vector3D Origin;
+        public Vector3D? Origin;
 
         /// <summary>
         /// Orientation (pitch yaw roll)
         /// </summary>
-        public QAngle Angles;
+        public QAngle? Angles;
 
         #endregion
 
@@ -90,7 +90,7 @@ namespace SabreTools.Models.BSP
         /// <summary>
         /// For lighting
         /// </summary>
-        public Vector3D LightingOrigin;
+        public Vector3D? LightingOrigin;
 
         #endregion
 
@@ -151,7 +151,7 @@ namespace SabreTools.Models.BSP
         /// <summary>
         /// Per instance color and alpha modulation
         /// </summary>
-        public ColorRGBExp32 DiffuseModulation;
+        public ColorRGBExp32? DiffuseModulation;
 
         #endregion
 
diff --git a/SabreTools.Models/BSP/Texdata.cs b/SabreTools.Models/BSP/Texdata.cs
index f6726d7..9476b0b 100644
--- a/SabreTools.Models/BSP/Texdata.cs
+++ b/SabreTools.Models/BSP/Texdata.cs
@@ -16,7 +16,7 @@ namespace SabreTools.Models.BSP
         /// <summary>
         /// RGB reflectivity
         /// </summary>
-        public Vector3D Reflectivity;
+        public Vector3D? Reflectivity;
 
         /// <summary>
         /// Index into TexdataStringTable
diff --git a/SabreTools.Models/BSP/VbspLeaf.cs b/SabreTools.Models/BSP/VbspLeaf.cs
index 29f8ad6..18c9ec5 100644
--- a/SabreTools.Models/BSP/VbspLeaf.cs
+++ b/SabreTools.Models/BSP/VbspLeaf.cs
@@ -83,7 +83,7 @@ namespace SabreTools.Models.BSP
         /// <summary>
         /// Precaculated light info for entities.
         /// </summary>
-        public CompressedLightCube AmbientLighting;
+        public CompressedLightCube? AmbientLighting;
 
         #endregion
 
diff --git a/SabreTools.Models/BSP/VbspModel.cs b/SabreTools.Models/BSP/VbspModel.cs
index 84cb3be..e3e4117 100644
--- a/SabreTools.Models/BSP/VbspModel.cs
+++ b/SabreTools.Models/BSP/VbspModel.cs
@@ -15,17 +15,17 @@ namespace SabreTools.Models.BSP
         /// <summary>
         /// Bounding box
         /// </summary>
-        public Vector3D Mins;
+        public Vector3D? Mins;
 
         /// <summary>
         /// Bounding box
         /// </summary>
-        public Vector3D Maxs;
+        public Vector3D? Maxs;
 
         /// <summary>
         /// For sounds or lights
         /// </summary>
-        public Vector3D OriginVector;
+        public Vector3D? OriginVector;
 
         /// <summary>
         /// Index into nodes
diff --git a/SabreTools.Models/BSP/VbspTexinfo.cs b/SabreTools.Models/BSP/VbspTexinfo.cs
index b0d1cd7..5acbb50 100644
--- a/SabreTools.Models/BSP/VbspTexinfo.cs
+++ b/SabreTools.Models/BSP/VbspTexinfo.cs
@@ -22,7 +22,7 @@ namespace SabreTools.Models.BSP
         /// <summary>
         /// Texture S-vector
         /// </summary>
-        public Vector3D TextureSVector;
+        public Vector3D? TextureSVector;
 
         /// <summary>
         /// Texture shift in the S direction
@@ -32,7 +32,7 @@ namespace SabreTools.Models.BSP
         /// <summary>
         /// Texture T-vector
         /// </summary>
-        public Vector3D TextureTVector;
+        public Vector3D? TextureTVector;
 
         /// <summary>
         /// Texture shift in the T direction
@@ -42,7 +42,7 @@ namespace SabreTools.Models.BSP
         /// <summary>
         /// Lightmap S-vector
         /// </summary>
-        public Vector3D LightmapSVector;
+        public Vector3D? LightmapSVector;
 
         /// <summary>
         /// Lightmap shift in the S direction
@@ -52,7 +52,7 @@ namespace SabreTools.Models.BSP
         /// <summary>
         /// Lightmap T-vector
         /// </summary>
-        public Vector3D LightmapTVector;
+        public Vector3D? LightmapTVector;
 
         /// <summary>
         /// Lightmap shift in the T direction
diff --git a/SabreTools.Models/BSP/WorldLight.cs b/SabreTools.Models/BSP/WorldLight.cs
index fd10eb9..69f7306 100644
--- a/SabreTools.Models/BSP/WorldLight.cs
+++ b/SabreTools.Models/BSP/WorldLight.cs
@@ -14,14 +14,14 @@ namespace SabreTools.Models.BSP
     [StructLayout(LayoutKind.Sequential)]
     public sealed class WorldLight
     {
-        public Vector3D Origin;
+        public Vector3D? Origin;
 
-        public Vector3D Intensity;
+        public Vector3D? Intensity;
 
         /// <summary>
         /// For surfaces and spotlights
         /// </summary>
-        public Vector3D Normal;
+        public Vector3D? Normal;
 
         public int Cluster;