[Unity plugin] Fix the missing .meta for copied library.

unity/Editor/Bindings/MujocoBinaryRetriever.cs

@@ -39,6 +39,7 @@ public class MujocoBinaryRetriever {
  "/Applications/MuJoCo.app/Contents/Frameworks" +
  "/mujoco.framework/Versions/Current/libmujoco.3.0.1.dylib",
  mujocoPath + "/mujoco.dylib");
+ GenerateMetaFile(mujocoPath + "/mujoco.dylib");
  AssetDatabase.Refresh();
  }
  } else if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux)) {
@@ -47,6 +48,7 @@ public class MujocoBinaryRetriever {
  Environment.GetFolderPath(Environment.SpecialFolder.UserProfile) +
  "/.mujoco/mujoco-3.0.1/lib/libmujoco.so.3.0.1",
  mujocoPath + "/libmujoco.so");
+ GenerateMetaFile(mujocoPath + "/libmujoco.so");
  AssetDatabase.Refresh();
  }
  } else {
@@ -55,11 +57,38 @@ public class MujocoBinaryRetriever {
  Environment.GetFolderPath(Environment.SpecialFolder.UserProfile) +
  "\\MuJoCo\\bin\\mujoco.dll",
  mujocoPath + "\\mujoco.dll");
+ GenerateMetaFile(mujocoPath + "\\mujoco.dll");
  AssetDatabase.Refresh();
  }
  }
  }
  }
  }
+
+ static void GenerateMetaFile(string file) {
+ string metaFileName = file + ".meta";
+
+ // Check if .meta file exists.
+ if (File.Exists(metaFileName)) {
+ Debug.Log("Meta file for " + file + " is already created!");
+ return;
+ }
+
+ // Create a uuid
+ var uuidN = Guid.NewGuid().ToString("N");
+
+ // Write content to .meta
+ using (StreamWriter writer = File.CreateText(metaFileName)) {
+ writer.WriteLine("fileFormatVersion: 2");
+ writer.WriteLine("guid: " + (uuidN.ToString()));
+ writer.WriteLine("DefaultImporter:");
+ writer.WriteLine(" externalObjects: {}");
+ writer.WriteLine(" userData: ");
+ writer.WriteLine(" assetBundleName: ");
+ writer.WriteLine(" assetBundleVariant: ");
+ }
+
+ Debug.Log("Meta file for " + file + " created!");
+ }
 }
 }