Sync conan versions and Texturebuilder work.

conanfile.py

@@ -18,7 +18,13 @@ class FBX2glTFConan(ConanFile):
     generators = "cmake_find_package", "cmake_paths"
 
     def configure(self):
-        pass
+        if (
+            self.settings.compiler == "gcc"
+            and self.settings.compiler.libcxx == "libstdc++"
+        ):
+            raise Exception(
+                "Rerun 'conan install' with argument: '-s compiler.libcxx=libstdc++11'"
+            )
 
     def build(self):
         cmake = CMake(self)

src/gltf/TextureBuilder.cpp

@@ -202,27 +202,24 @@ std::shared_ptr<TextureData> TextureBuilder::simple(int rawTexIndex, const std::
       image = new ImageData(relativeFilename, *bufferView, mimeType);
     }
 
-  } else if (!relativeFilename.empty()) {    
+  } else if (!relativeFilename.empty()) {
     std::string outputPath = outputFolder + "/" + relativeFilename;
     auto dstAbs = FileUtils::GetAbsolutePath(outputPath);
     image = new ImageData(relativeFilename, relativeFilename);
     auto srcAbs = FileUtils::GetAbsolutePath(rawTexture.fileLocation);
-    if (!FileUtils::FileExists(outputPath) && srcAbs != dstAbs) {
-      if (FileUtils::CopyFile(rawTexture.fileLocation, outputPath, true)) {
-        if (verboseOutput) {
-          fmt::printf("Copied texture '%s' to output folder: %s\n", textureName, outputPath);
-        }
-      } else {
-        // no point commenting further on read/write error; CopyFile() does enough of that, and we
-        // certainly want to to add an image struct to the glTF JSON, with the correct relative
-        // path reference, even if the copy failed.
-      }
+    if (FileUtils::FileExists(outputPath) || srcAbs == dstAbs)) {
+      return nullptr;
     }
-  }
+    if (!FileUtils::CopyFile(rawTexture.fileLocation, outputPath, true)) {
+      return nullptr;
+    }
+    if (verboseOutput) {
+      fmt::printf("Copied texture '%s' to output folder: %s\n", textureName, outputPath);
+    }
+  }  
   if (!image) {
     return nullptr;
   }
-
   std::shared_ptr<TextureData> texDat = gltf.textures.hold(
       new TextureData(textureName, *gltf.defaultSampler, *gltf.images.hold(image)));
   textureByIndicesKey.insert(std::make_pair(key, texDat));