diff --git a/src/FBX2glTF.h b/src/FBX2glTF.h
index 27278eb..ebdfe77 100644
--- a/src/FBX2glTF.h
+++ b/src/FBX2glTF.h
@@ -18,6 +18,8 @@
 #include <Windows.h>
 #endif
 
+const std::string FBX2GLTF_VERSION = "0.9.5";
+
 #include <fmt/printf.h>
 #include <fbxsdk.h>
 
diff --git a/src/Fbx2Raw.cpp b/src/Fbx2Raw.cpp
index 2b072d0..3f041e2 100644
--- a/src/Fbx2Raw.cpp
+++ b/src/Fbx2Raw.cpp
@@ -1263,7 +1263,7 @@ static void ReadAnimations(RawModel &raw, FbxScene *pScene)
                         for (int targetIx = 0; targetIx < targetCount; targetIx++) {
                             if (curve) {
                                 float result = findInInterval(influence, targetIx-1);
-                                if (!isnan(result)) {
+                                if (!std::isnan(result)) {
                                     // we're transitioning into targetIx
                                     channel.weights.push_back(result);
                                     hasMorphs = true;
@@ -1271,7 +1271,7 @@ static void ReadAnimations(RawModel &raw, FbxScene *pScene)
                                 }
                                 if (targetIx != targetCount-1) {
                                     result = findInInterval(influence, targetIx);
-                                    if (!isnan(result)) {
+                                    if (!std::isnan(result)) {
                                         // we're transitioning AWAY from targetIx
                                         channel.weights.push_back(1.0f - result);
                                         hasMorphs = true;
diff --git a/src/Raw2Gltf.cpp b/src/Raw2Gltf.cpp
index 0b7094a..b7d2cbd 100644
--- a/src/Raw2Gltf.cpp
+++ b/src/Raw2Gltf.cpp
@@ -1190,11 +1190,13 @@ ModelData *Raw2Gltf(
             extensionsRequired.push_back(KHR_DRACO_MESH_COMPRESSION);
         }
 
-        json glTFJson{
-            {"asset", {{"generator", "FBX2glTF"}, {"version", "2.0"}}},
-            {"scene", rootScene.ix}};
-        if (!extensionsUsed.empty())
-        {
+        json glTFJson {
+          { "asset", {
+              { "generator", "FBX2glTF v" + FBX2GLTF_VERSION },
+              { "version", "2.0" }}},
+          { "scene", rootScene.ix }
+        };
+        if (!extensionsUsed.empty()) {
             glTFJson["extensionsUsed"] = extensionsUsed;
         }
         if (!extensionsRequired.empty())
diff --git a/src/RawModel.cpp b/src/RawModel.cpp
index 230b180..148776d 100644
--- a/src/RawModel.cpp
+++ b/src/RawModel.cpp
@@ -269,11 +269,20 @@ void RawModel::Condense()
 
         surfaces.clear();
 
+        std::set<int> survivingSurfaceIds;
         for (auto &triangle : triangles) {
+            int oldSurfaceIndex = triangle.surfaceIndex;
             const RawSurface &surface = oldSurfaces[triangle.surfaceIndex];
             const int surfaceIndex = AddSurface(surface.name.c_str(), surface.id);
             surfaces[surfaceIndex] = surface;
             triangle.surfaceIndex = surfaceIndex;
+            survivingSurfaceIds.emplace(surface.id);
+        }
+        // clear out references to meshes that no longer exist
+        for (auto &node : nodes) {
+            if (node.surfaceId != 0 && survivingSurfaceIds.find(node.surfaceId) == survivingSurfaceIds.end()) {
+                node.surfaceId = 0;
+            }
         }
     }
 
@@ -341,7 +350,9 @@ void RawModel::TransformGeometry(ComputeNormalsOption normals)
 
             if (verboseOutput) {
                 if (normals == ComputeNormalsOption::BROKEN) {
-                    fmt::printf("Repaired %lu empty normals.\n", computedNormalsCount);
+                    if (computedNormalsCount > 0) {
+                        fmt::printf("Repaired %lu empty normals.\n", computedNormalsCount);
+                    }
                 } else {
                     fmt::printf("Computed %lu normals.\n", computedNormalsCount);
                 }
diff --git a/src/main.cpp b/src/main.cpp
index f090672..107c68a 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -34,7 +34,8 @@ int main(int argc, char *argv[])
 {
     cxxopts::Options options(
         "FBX2glTF",
-        "FBX2glTF 2.0: Generate a glTF 2.0 representation of an FBX model.");
+        fmt::sprintf("FBX2glTF %s: Generate a glTF 2.0 representation of an FBX model.", FBX2GLTF_VERSION)
+    );
 
     std::string inputPath;
     std::string outputPath;
@@ -98,11 +99,7 @@ int main(int argc, char *argv[])
     }
 
     if (options.count("version")) {
-        fmt::printf(
-            R"(
-FBX2glTF version 2.0
-Copyright (c) 2016-2017 Oculus VR, LLC.
-)");
+        fmt::printf("FBX2glTF version %s\nCopyright (c) 2016-2017 Oculus VR, LLC.\n", FBX2GLTF_VERSION);
         return 0;
     }